Ch.6 - Thermochemistry See all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Calorimetry

See all sections
Sections
Internal Energy
Calorimetry
Hess's Law
Enthalpy of Formation
End of Chapter 6 Problems
Additional Practice
Units of Energy
Endothermic & Exothermic Reactions
Additional Guides
Enthalpy

Both heat capacity (C) and specific heat capacity (c) deal with the amount of heat required to change a compound’s temperature by 1 Kelvin. Specific heat capacity (c) deals with changing 1 gram of a compound.

Constant Volume Calorimetry

By using calorimetry we can measure the thermal energy of a reaction (system) by measuring the change in heat of the surroundings.

Concept #1: Heat capacity vs. Specific Heat Capacity

Concept #2: Bomb Calorimeter

A bomb calorimeter measures the amount of calories within a substance through combustion. In other words, we “blow it up” and measure the amount of heat it releases. 

Constant Volume-Calorimetry Calculations

If you are given energy or heat, with specific heat capacity and mass then you will most likely use q = mcΔT.

Example #1: In an experiment a 9.87 carat (1 carat = 0.200g) diamond is heated to 72.25oC and immersed in 22.08 g of water in a calorimeter. If the initial temperature of the water was 31.0oC what is the final temperature of the water? (cdiamond = 0.519) (cwater = 4.184 ). 

Practice: A sample of copper absorbs 35.3 kJ of heat, which increases the temperature by 25 degrees Celsius, determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J/g *C.

When dealing with heat it is important to remember that if one compound is gaining heat that means another compound is losing heat.

Practice: 50.00 g of heated metal ore is placed into an insulated beaker containing 822.5 g of water. Once the metal heats up the final temperature of the water is 32.08 degrees Celsius. If the metal gains 14.55 kJ of energy, what is the initial temperature of the water?

Constant Pressure Calorimetry

The enthalpy or heat of a reaction can be calculated through the use of a coffee cup calorimeter. 

Concept #3: Coffee Cup Calorimeter

Concept #4: Calculating the Heat of the Solution

The heat of the solution can be determined by first determining the heat of water

Concept #5: Calculating the enthalpy of the reaction

Additional Problems
Two solids of equal mass, labeled X and Y, are placed in contact with each other. Solid X  has an initial temperature of 100°C and  Solid Y has an initial temperature of 25°C. After some time, both solids are at 40°C. Which statement is correct regarding the direction of heat transfer and specific heat capacity (Assume heat transfers only between X and Y):   Direction of heat transfer                       Specific heat capacity A.                From X to Y                                          X has greater heat capacity B.                From X to Y                                          Y has greater heat capacity C.                From Y to X                                          X has greater heat capacity D.                From Y to X                                          Y has greater heat capacity
How much energy is required to change the temperature of  21.5 g Cu from 27 to 88.1 °C? The specific heat capacity of copper is 0.385 J/gK. 223 J 506 J 641 J 729 J 3.41 x 103
The molar heat capacity of silver is 25.35 J/mol•°C. Calculate how much energy (in kJ) it would take to raise the temperature of 15.7 g of the silver metal by 17.2 °C.    
Three separate 3.5g blocks of Al, Cu, and Fe at 25 °C each absorb 0.505 kJ of heat. Which block reaches the highest temperature? The specific heats of Al, Cu, and Fe are 0.900 J/g•°C, 0.385J/g•°C, and 0.444 J/g•°C, respectively. a) Fe b) Fe and Cu c) Al and Cu d) Al e) Cu
Adding water to a steel pan on a flame slows the rise in temerature of the pan, which of the following concepts does this represent? A. Heat capacity is an intensive property B. Heat capacity is an extensive property C. The example does not relate to heat capacity D. Temperature is a state function
When a 45.0 g sample of an alloy at 100.0 °C is dropped into 100.0 g of water at 25.0 °C, the final temperature is 37.0 °C. What is the specific heat of the alloy? The specific heat of water is 4.184 J•g-1•°C-1 a) 0.423 J•g-1•°C-1 b) 1.77 J•g-1•°C-1 c) 9.88 J•g-1•°C-1 d) 48.8 J•g-1•°C-1
Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter. The reaction causes the teperature of the resulting solution to fall below room temperature. Which of the following statements is TRUE? a) The products have a lower potential energy than the reactants. b) This type of experiment will provide data to calculate ΔE rxn.  c) The reaction is exothermic.  d) Energy is leaving the system during the reaction.  e) None of the above statements is true.      The same reaction in a bomb and coffee-cup calorimeter : a) will give the same value for ΔH rxn because it is the same reaction.  b) will give the same value for ΔH rxn because both systems are identical. c) will give the same values because both systems are at a constant pressure.  d) will give slightly different values because the coffee-cup calorimeter will do some PV work.  e) will give slightly different values because the bomb calorimeter will do some PV work. 
Calculate q (in kJ) when 2.00 g of water is heated from 37°C to 47°C. The specific heat capacity of water is 4.184 J/g.°C.
A 1.00 g sample of NH 4NO3 is decomposed in a bomb calorimeter. The temperature increases by 6.12°C. What is the molar heat of decomposition for ammonium nitrate? a) -602 kJ•mol-1 b) -398 kJ•mol-1 c) 7.53 kJ•mol-1 d) 164 kJ•mol-1
Which substance (with specific heat capacity provided) would show the smallest temperature change upon gaining 200.0 J of heat? a) 50.0 g Al, CAl = 0.903 J/g°C b) 50.0 g Cu, CCu = 0.385 J/g°C c) 25.0 g granite, Cgranite = 0.79 J/g°C d) 25.0 g Au, CAu = 0.128 J/g°C e) 25.0 g Ag, CAg = 0.235 J/g°C  
If three samples of silver, one with a mass of 10.0 grams, another with a mass of 50.0 grams and a third with a mass of 100.0 grams each absorb 36.3 kJ of heat which sample will experience the greatest increase in temperature? The 10.0 gram sample The 50.0 gram sample The 100.0 gram sample Each will have the same increase in temperature Depends on the starting temperature of each
When a fresh breath of air is drawn into the lungs, it is heated by your body. Let’s assume it reaches thermal equilibrium with your body temperature of 37°C. Given the temperature, pressure, and the average molar mass of air, you could easily calculate that your breath of 0.48 L corresponds to 0.51 g of air. The specific heat of air is 1.0 J/g•°C. I. Given that the temperature outside is 21°C, how much heat is required to take the air in your 0.48 L breath from 21°C to 37°C?            II. The heat calculated in the previous question is lost every time you exhale. Assuming 15 breaths per minute, how much heat would be lost in one day by exhaling? Furthermore, assuming a daily energy intake of 8400 kJ (corresponding to 2000 food Calories), what percent of your daily energy intake is lost as heat due to exhaling during a 24 hour period?
How much heat is absorbed by a pan made of iron, with a mass of 150 g whose temperature rises from 25.0°C to 100.0°C?
A student constructs a "coffee cup" calorimeter that contains 83.6 grams of water, at 19.7°C, in a double cup set up with a thermometer and a cork cover. A piece of copper with a mass of 101.7 grams was heated to a certain temperature and placed in the calorimeter. Then the calorimeter was allowed to equilibrate and the thermometer recorded a temperature of 28.3 °C after the equilibration. Determine the temperature to which the copper piece was heated initially. (The specific heat of copper is 0.385 J/g °C and the specific heat of water is 4.184 J/g °C) a. 105.1 °C b. 85.4 °C c. 142.0 °C d. 29.0 °C e. 48.5 °C
In a bomb calorimeter, reactions are carried out at: (A) constant pressure  (B) constant volume (C) 1 atm pressure and 25°C (D) 1 atm pressure and 0°C
Determine the specific heat capacity of an alloy that requires 59.3 kJ to raise the temperature of 150.0 g alloy from 298 K to 398 K. A) 3.95 J/g°C B) 1.87 J/g°C C) 2.29 J/g°C D) 2.53 J/g°C E) 4.38 J/g°C
When 75.4 J of energy is absorbed by 0.25 mol of CCl 4, what is the temperature change of CCl4? The specific heat capacity of CCl 4 is 0.861 J/g·°C. Molar mass of CCl 4 is 153.81 g/mol. A) 17.8°C            B) 21.9°C    C) 2.3°C         D) 9.1°C         E) 44.6°C
Suppose a 50.0 g block of silver at 100°C is placed in contact with a 50.0 g block of iron at 0°C, and the two blocks are insulated from the rest of the universe.  The final temperature of the two blocks  A)    will be higher than 50°C.  B)    will be lower than 50°C.  C)    will be exactly 50°C.  D)    is unrelated to the composition of the blocks.  E)    cannot be predicted.
Which of the following statements are correct? A. specific heat capacity is defined as the amount of heat energy required to raise the temperature of an object 1K B. under conditions of constant pressure, no work is done on or by the system C. molar heat capacity is defined as the amount of heat energy required to raise the temperature of 1 mole of a substance 1K D. heat is always transferred from an object with a lower temperature to an object with a higher temperature
The combustion of toluene has a ∆Erxn of -3.91 x 103 kJ/mol. When 1.55 g of toluene (C7H8) undergoes combustion in a bomb calorimeter, the temperature rises from 23.12 °C to 37.57 °C. Find the heat capacity of the bomb calorimeter. 
If it takes 0.216 kJ of heat to raise the temperature of a 12.0 g piece of Al from 15.5 to 35.5 oC, what is the specific heat (J/g K) of Al?
A chemistry student weighs a rock and finds its mass to be 4.7 g. She then finds that upon absorption of 57.2 J of heat, the temperature of the rock rises from 25°C to 57°C. Find the specific heat capacity of the substance composing the rock. 
When 1.550 g of liquid hexane (C6H14) undergoes combustion in a bomb calorimeter, the temperature rises from 25.87 to 38.13 °C. Find the ∆Erxn in kJ/mol of hexane. The heat capacity of the bomb calorimeter was found in a different experiment to be 5.73 kJ/°C. 
Determine the final temperature when a 25.0 g piece of iron at 85.0°C is placed into 75.0 g of water at 20.0°C. The heat capacity of the iron is 0.450 J/g °C. 
When 68.00 J of energy are added to a sample of Gallium that is initially at 25°C, the temperature rises to 38.0° C. What is the volume of the sample? The specific heat of Gallium is 0.372 J•g -1•°C-1. Density of Gallium is 5.904 g•cm–3. a) 2.38 cm3 b) 4.28 cm3 c) 14.1 cm3 d) 31.0 cm3
A 19.78 g piece of nickel (specific heat of nickel = 0.444 J/g  oC) was heated to 103.5 oC and then plunged into a beaker containing 87.9 grams of water at 14.7  oC. Determine the final temperature of the metal after the system attains thermal equilibrium. (the specific heat of water is 4.184 J/g oC) A. 59.1 oC B. 44.4 oC C. 16.8 oC D. 12.5 oC E. 55.6 oC
The specific heat of copper metal is 0.385 J/g K. How many joules of heat are necessary to raise the temperature of a 1.42-kg block of copper from 25.0 °C to 88.5 °C? A) 3.47 x 104 J B) 34.7 J C) 2.34 x 105 J D) 8.46 J
A student mixes 100 mL of 0.50 M NaOH with 100 mL 0f 0.50 M HCl in a Styrofoam® cup and observes a temperature increase of ΔT1. When she repeats this experiment using 200 mL of each solution, she observes a temperature change of ΔT2. If no heat is lost to the surroundings or absorbed by the Styrofoam® cup, what is the relationship between ΔT1 and ΔT2? a) ΔT2 = 4 ΔT1 b) ΔT2 =  2 ΔT1 c) ΔT2 = 0.5 ΔT1 d) ΔT2  = ΔT1
In constant-volume calorimetry, what is FALSE?   a. There is no work performed. b. The total energy is measured by the change in pressure. c. The total energy is determined only by heat. d. The heat capacity of the calorimeter needs to be known in order to determine the heat. e. All of the above are true.
Which substance (with specific heat capacity provided) would show the smallest temperature change upon gaining 200.0 J of heat? a. 50.0 g Al, CAl = 0.903 J/g°C b. 50.0 g Cu, CCu = 0.385 J/g°C c. 25.0 g granite, Cgranite = 0.79 J/g°C d. 25.0 g Au, CAu = 0.128 J/g°C e. 25.0 g Ag, CAg – 0.235 J/g°C
More heat is derived from cooling one gram of steam at 100°C to water at 50°C than from cooling one gram of liquid water at 100°C to 50°C because a) the steam is hotter than the water. b) the steam occupies a greater volume than the water.  c) the density of water is greater than that of steam.  d) the heat of condensation is evolved. 
A sample of 1.67 grams of compound Y is burned completely in a bomb calorimeter which contains 2500 g of water. The temperature rises from 24.273ºC to 24.587ºC. What is ∆Urxn for the combustion of compound Y? The hardware component of the calorimeter has a heat capacity of 3.29 kJ/ºC. The specific heat of water is 4.184 J/g·ºC, and the MW of Y is 117 g/mol. 1. -344.7 2. -615.4 3. -392.1 4. -322.0 5. -302.5 6. -185.4 7. -482.0 8. -652.5 9. -278.2 10. -424.3
The same reaction in a bomb and coffee-cup calorimeter: a. will give the same value of Hrxn because it is the same reaction. b. will give the same value for Hrxn because both systems are identical. c. will give the same values because both systems are at constant temperature. d. will give slightly different values because the coffee-cup calorimeter will do some PV work. e. will give slightly different values because the bomb calorimeter will do some PV work
A total of 2.25 moles of a compound are allowed to react with water in a foam coffee cup and the reaction produces 83.1 g of solution. The addition of the compound caused the temperature of the solution to increase from 20.5 oC to 32.1 oC. What is the enthalpy of the reaction? Assume no heat is transferred or lost to the surroundings or to the foam coffee cup. The specific heat of the solution is 4.184 J/(g×oC) . 
A piece of iron (mass = 100.0 g) at 398 K is placed in a Styrofoam coffee cup calorimeter containing 25.0 mL of water 298 K. Assuming that no heat is lost to the cup, what will be the final temperature of the water? The specific heat capacity of iron = 0.449 J/gºC. A. 308 K B. 328 K C. 338 K D. 368 K E. 388 K
The molar heat capacity of silver is 25.35 J/mol × oC . Calculate how much energy (in kJ) it would take to raise the temperature of 15.7 g of the silver metal by 17.2 oC. 
Which of the following substances (with specific heat capacity provided) would show the greatest temperature change upon absorbing 100.0 J of heat? a) 10.0 g Ag, CAg = 0.235 J/g°C b) 10.0 g H2O, CH2O = 4.18 J/g°C c) 10.0 g ethanol, Cethanol = 2.42 J/g°C d) 10.0 g Fe, CFe = 0.449 J/g°C e) 10.0 g Au, CAu = 0.128 J/g°C
How much energy must be transferred to raise the temperature of a cup of coffee that is 250 mL from 20.5 °C to 368.8 K? Assume that water and coffee have the same density 1.00 g/mL and specific heat capacity (4.184 J/g•K).
A 55.0-g piece of metal is heated in boiling water to 99.8 °C and then dropped into cool water in an insulated beaker containing 225 mL of water with an initial temperature of 21.0 °C. The final temperature of the metal and water is 23.1 °C, what is the specific heat capacity of the metal?
A 0.3423 g sample of pentane, C5H12, was burned in a bomb calorimeter. The temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22ºC to 22.82ºC. The heat capacity of the calorimeter is 2.21 kJ/ºC. The heat capacity of water = 4.184 J/gºC. How much heat was given off during combustion of the sample of pentane? 1) 8.8 kJ 2) -8.8 kJ 3) 16.6 J 4) 16.6 kJ 5) 3.1415 kJ
What is heat capacity?
Explain the difference between heat capacity and specific heat capacity.
Explain how the high specific heat capacity of water can affect the weather in coastal versus inland regions.
What are the units of molar heat capacity?
What are the units of specific heat?
If you know the specific heat of copper, what additional information do you need to calculate the heat capacity of a particular piece of copper pipe?
Two solid objects, A and B, are placed in boiling water and allowed to come to temperature there. Each is then lifted out and placed in separate beakers containing 1000 g water at 10.0 oC. Object A increases the water temperature by 3.50 oC; B increases the water temperature by 2.60 oC. You may want to reference (Pages 179 - 183) Section 5.5 while completing this problem.Which object has the greater heat capacity?        
What is the specific heat of liquid water?
Table 5.2 Specific Heats of Some Substances at 298 K Elements Substance Specific Heat (J/g K) N2(g) 1.04 Al(s) 0.90 Fe(s) 0.45 Hg(l) 0.14 Compounds Substance Specific Heat (J/g K) H2O(l) 4.18 CH4(g) 2.20 CO2(g) 0.84 CaCO3(s) 0.82 You may want to reference (Pages 179 - 183) Section 5.5 while completing this problem.Which substance in Table 5.2 requires the smallest amount of energy to increase the temperature of 50.5 g of that substance by 13 K?
We pack two identical coolers for a picnic, placing 24 12-ounce soft drinks and five pounds of ice in each. However, the drinks that we put into cooler A were refrigerated for several hours before they were packed in the cooler, while the drinks that we put into cooler B were at room temperature. When we open the two coolers three hours later, most of the ice in cooler A is still present, while nearly all of the ice in cooler B has melted.Explain this difference.
Elements Compounds Substance Specific Heat (J/g-K) Substance Specific Heat (J/g-K) N2(g) 1.04 H2O(l) 4.18 Al(s) 0.90 CH4(g) 2.20 Fe(s) 0.45 CO2(g) 0.84 Hg(l) 0.14 CaCO3(s) 0.82 Table Specific Heats of Some Substances at 298 K Which substance in the table undergoes the greatest temperature change when the same mass of each substance absorbs the same quantity of heat?
Nutrition label for whole milk.Which value would change most if this label were for skim milk instead of whole milk: grams of fat, grams of total carbohydrate, or grams of protein?
Which releases the greatest amount of energy per gram when metabolized: carbohydrates, proteins, or fats?
Assuming that there is an uncertainty of 0.002 oC in each temperature reading and that the masses of samples are measured to 0.001 g, what is the estimated uncertainty in the value calculated for the heat of combustion per mole of caffeine?
What is calorimetry?
Explain the difference between a coffee-cup calorimeter and a bomb calorimeter.
Is the change in enthalpy for a reaction an extensive property?
In order to obtain the largest possible amount of heat from a chemical reaction in which there is a large increase in the number of moles of gas, should you carry out the reaction under conditions of constant volume or constant pressure?
A sample of a hydrocarbon is combusted completely in O2(g) to produce 24.01 g CO2(g), 4.917 g H2O(g), and 342 kJ of heat.Do you think that the hydrocarbon is one of those listed in Appendix C? Explain your answer.
The same reaction, with exactly the same amount of reactant, is conducted in a bomb calorimeter and in a coffee-cup calorimeter. In one of the calorimeters, qrxn = -12.5 kJ and in the other qrxn = -11.8 kJ. Which value was obtained in the bomb calorimeter? (Assume that the reaction has a positive V in the coffee-cup calorimeter.)
The specific heat of octane, C8H18 (l), is 2.22 J/g K.Which will require more heat, increasing the temperature of 1 mol of C8H18 (l) by a certain amount or increasing the temperature of 1 mol of H2O (l) by the same amount?
Under constant-volume conditions the heat of combustion of benzoic acid (C6H5COOH) is 26.38 kJ/g. A 2.760 -g sample of benzoic acid is burned in a bomb calorimeter. The temperature of the calorimeter increases from 21.50 oC to 29.95 oC.Suppose that in changing samples, a portion of the water in the calorimeter were lost. In what way, if any, would this change the heat capacity of the calorimeter?
Coffee-cup calorimeter. This simple apparatus is used to measure temperature changes of reactions at constant pressure.Propose a reason for why two Styrofoam cups are often used instead of just one.
Bomb calorimeter.Why is a stirrer used in calorimeters?
A 100.0-g bar of gold is heated from 25 oC to 50 oC, during which it absorbs 322 J of heat. Assume the volume of the gold bar remains constant. You may want to reference (Pages 179 - 183) Section 5.5 while completing this problem.Suppose that the same amount of heat is added to two 10.0-g blocks of metal, both initially at the same temperature. One block is gold metal, and one is iron metal. Which block will have the greater rise in temperature after the addition of the heat? (Note that the specific heat of iron is 0.451 J/g oC.)
Hess’s law provides a useful means of calculating energy changes that are difficult to measure directly. For instance, it is impossible to measure directly the enthalpy for the combustion of carbon to form carbon monoxide. Combustion of 1 mol of carbon with 0.5 mol of O2 produces both CO and CO2, leaving some carbon unreacted. However, solid carbon and carbon monoxide can both be completely burned in O2 to produce CO2.We can therefore use the enthalpy changes of these reactions to calculate the heat of combustion of carbon.What effect does this change have on Delta{ m H}: a reversing reaction?
Hess’s law provides a useful means of calculating energy changes that are difficult to measure directly. For instance, it is impossible to measure directly the enthalpy for the combustion of carbon to form carbon monoxide. Combustion of 1 mol of carbon with 0.5 mol of O2 produces both CO and CO2, leaving some carbon unreacted. However, solid carbon and carbon monoxide can both be completely burned in O2 to produce CO2.We can therefore use the enthalpy changes of these reactions to calculate the heat of combustion of carbon.What effect does this change have on Delta{ m H}: multiplying the coefficients of the equation for the reaction by 2?
Enthalpy diagram for combustion of 1 mol of methane. The enthalpy change of the one-step reaction equals the sum of the enthalpy changes of the reaction run in two steps: -890 kJ = -802 kJ + (-88 kJ).What process corresponds to the -88 kJ enthalpy change?
What is meant by the term fuel value?
Which is a greater source of energy as food, 5 g of fat or 9 g of carbohydrate?
Under constant-volume conditions the heat of combustion of benzoic acid (C6H5COOH) is 26.38 kJ/g. A 2.760 -g sample of benzoic acid is burned in a bomb calorimeter. The temperature of the calorimeter increases from 21.50 oC to 29.95 oC.A 1.460 -g sample of a new organic substance is combusted in the same calorimeter. The temperature of the calorimeter increases from 22.14 oC to 27.09 oC. What is the heat of combustion per gram of the new substance?
A coffee-cup calorimeter contains 150.0 g of water at 25.2 oC . A 123.0-g block of copper metal is heated to 100.4 oC by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.2 oC .What would be the final temperature of the system if all the heat lost by the copper block were absorbed by the water in the calorimeter?
You may want to reference (Pages 259 - 264) Section 6.4 while completing this problem.A block of copper of unknown mass has an initial temperature of 65.1 oC. The copper is immersed in a beaker containing 95.1 g of water at 22.8 oC. When the two substances reach thermal equilibrium, the final temperature is 24.6 oC. What is the mass of the copper block? Assume that Cs, H2O = 4.18 J/(g ) and Cs, Cu = 0.385 J/(g ).
A silver block, initially at 57.6 oC, is submerged into 100.0 g of water at 24.7 oC, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 27.0 oC.What is the mass of the silver block?
A 31.5 g wafer of pure gold initially at 69.7 oC is submerged into 63.6 g of water at 27.2 oC in an insulated container.What is the final temperature of both substances at thermal equilibrium?
Two substances, A and B, initially at different temperatures, come into contact and reach thermal equilibrium. The mass of substance A is 6.23 g and its initial temperature is 20.6 oC. The mass of substance B is 25.6 g and its initial temperature is 52.5 oC. The final temperature of both substances at thermal equilibrium is 46.6 oC.If the specific heat capacity of substance B is 1.17 J/g oC, what is the specific heat capacity of substance A?
A 2.56 g sample of a substance suspected of being pure gold is warmed to 72.4 oC and submerged into 15.6 g of water initially at 24.6 oC. The final temperature of the mixture is 26.6 oC.What is the heat capacity of the unknown substance?
A 2.56 g sample of a substance suspected of being pure gold is warmed to 72.4 oC and submerged into 15.6 g of water initially at 24.6 oC. The final temperature of the mixture is 26.6 oC.Could the substance be pure gold?
A 26.0 -g aluminum block is warmed to 65.5 oC and plunged into an insulated beaker containing 55.3 g water initially at 22.2 oC. The aluminum and the water are allowed to come to thermal equilibrium.Assuming that no heat is lost, what is the final temperature of the water and aluminum?
A copper cube with an edge measuring 1.57 cm and an aluminum cube with an edge measuring 1.66 cm are both heated to 57.6 oC and submerged in 100.0 mL of water at 21.9 oC.What is the final temperature of the water when equilibrium is reached? (Assume a density of 0.998 g/mL for water.)
A coffee-cup calorimeter contains 150.0 g of water at 25.2 oC . A 123.0-g block of copper metal is heated to 100.4 oC by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.2 oC .The difference between your answers for (a) and (b) is due to heat loss through the Styrofoam cups and the heat necessary to raise the temperature of the inner wall of the apparatus. The heat capacity of the calorimeter is the amount of heat necessary to raise the temperature of the apparatus (the cups and the stopper) by 1 K. Calculate the heat capacity of the calorimeter in J/K.
To determine whether a shiny gold-colored rock is actually gold, a chemistry student decides to measure its heat capacity. She first weighs the rock and finds it has a mass of 4.0 g . She then finds that upon absorption of 54.6 J of heat, the temperature of the rock rises from 25 oC to 56 oC. Substance Specific heat capacity, Cs (J/(g oC))* Elements Lead 0.128 Gold 0.128 Silver 0.235 Copper 0.385 Iron 0.449 Aluminum 0.903 Compounds Ethanol 2.42 Water 4.18 Materials Glass (Pyrex) 0.75 Granite 0.79 Sand 0.84 * At 298 K. Find the specific heat capacity of the substance composing the rock.
To determine whether a shiny gold-colored rock is actually gold, a chemistry student decides to measure its heat capacity. She first weighs the rock and finds it has a mass of 4.0 g . She then finds that upon absorption of 54.6 J of heat, the temperature of the rock rises from 25 oC to 56 oC. Substance Specific heat capacity, Cs (J/(g oC))* Elements Lead 0.128 Gold 0.128 Silver 0.235 Copper 0.385 Iron 0.449 Aluminum 0.903 Compounds Ethanol 2.42 Water 4.18 Materials Glass (Pyrex) 0.75 Granite 0.79 Sand 0.84 * At 298 K. Determine whether the value is consistent with the rock being pure gold by referring to the table.
How much heat is required to warm 1.50 L of water from 26.0 oC to 100.0 oC? (Assume a density of 1.0/mL for the water.)
Suppose that 26 g of each of the following substances is initially at 28.0 oC. What is the final temperature of each substance upon absorbing 2.40 kJ of heat?gold
Suppose that 26 g of each of the following substances is initially at 28.0 oC. What is the final temperature of each substance upon absorbing 2.40 kJ of heat?silver
Suppose that 26 g of each of the following substances is initially at 28.0 oC. What is the final temperature of each substance upon absorbing 2.40 kJ of heat?aluminum
Suppose that 26 g of each of the following substances is initially at 28.0 oC. What is the final temperature of each substance upon absorbing 2.40 kJ of heat?water
A house is designed to have passive solar energy features. Brickwork is to be incorporated into the interior of the house to act as a heat absorber. Each brick weighs approximately 1.8 kg. The specific heat of the brick is 0.85 J/g.How many bricks must be incorporated into the interior of the house to provide the same total heat capacity as 1800 gal of water?
From the following data for three prospective fuels, calculate which could provide the most energy per unit volume: Fuel Density at 20oC (g/cm3) Molar Enthalpy of Combustion kJ/mol Nitroethane, C2 H5 NO2 (l) 1.052 - 1368 Ethanol, C2 H5 OH(l) 0.789 - 1367 Methylhydrazine, CH6 N2 (l) 0.874 - 1305
One tablespoon of peanut butter has a mass of 17 g . It is combusted in a calorimeter whose heat capacity is 130 kJ/oC . The temperature of the calorimeter rises from 22.3 oC to 25.5 oC.Find the food caloric content of peanut butter.
The hydrocarbons acetylene (C2 H2 ) and benzene (C6 H6 ) have the same empirical formula. Benzene is an "aromatic" hydrocarbon, one that is unusually stable because of its structure.Determine the fuel value in kJ/g for acetylene.
The hydrocarbons acetylene (C2 H2 ) and benzene (C6 H6 ) have the same empirical formula. Benzene is an "aromatic" hydrocarbon, one that is unusually stable because of its structure.Determine the fuel value in kJ/g for benzene.
Three common hydrocarbons that contain four carbons are listed here, along with their standard enthalpies of formation: Hydrocarbon Formula Hf(kJ/mol) 1,3-Butadiene C4 H6 (g) 111.9 1-Butene C4 H8 (g) 1.2 n-Butane C4 H10 (g) -124.7 For 1-Butene calculate the fuel value in kJ/g.
Three common hydrocarbons that contain four carbons are listed here, along with their standard enthalpies of formation: Hydrocarbon Formula Hf(kJ/mol) 1,3-Butadiene C4 H6 (g) 111.9 1-Butene C4 H8 (g) 1.2 n-Butane C4 H10 (g) -124.7 For n-Butane calculate the fuel value in kJ/g..
The heat of vaporization of water at 373 K is 40.7 kJ/mol.Find q for the evaporation of 451 g of water at this temperature.
The heat of vaporization of water at 373 K is 40.7 kJ/mol.Find w for the evaporation of 451 g of water at this temperature.
A sample of a hydrocarbon is combusted completely in O2(g) to produce 24.01 g CO2(g), 4.917 g H2O(g), and 342 kJ of heat.What is the mass of the hydrocarbon sample that was combusted?
You may want to reference (Page 258) Section 6.4 while completing this problem.How much heat must be absorbed by a 21.0 g sample of water to raise its temperature from 21.0 oC to 51.0 oC? (For water, Cs =4.18 J/g oC.)
Assume that the kinetic energy of a 1400 kg car moving at 111 km/h is converted entirely into heat.What amount of water in liters could be heated from 20.0 C to 50.0 C by the car’s energy? (One calorie raises the temperature of 1 mL of water by 1 C.)
Two solid objects, A and B, are placed in boiling water and allowed to come to temperature there. Each is then lifted out and placed in separate beakers containing 1000 g water at 10.0 oC. Object A increases the water temperature by 3.50 oC; B increases the water temperature by 2.60 oC. You may want to reference (Pages 179 - 183) Section 5.5 while completing this problem.What can you say about the specific heats of A and B?        
What is the molar heat capacity of liquid water?
What is the heat capacity of 175 g of liquid water?
How many kJ of heat are needed to raise the temperature of 13.00 kg of liquid water from 24.5 oC to 46.5 oC?
Table 5.2 Specific Heats of Some Substances at 298 K Elements Substance Specific Heat (J/g K) N2(g) 1.04 Al(s) 0.90 Fe(s) 0.45 Hg(l) 0.14 Compounds Substance Specific Heat (J/g K) H2O(l) 4.18 CH4(g) 2.20 CO2(g) 0.84 CaCO3(s) 0.82 You may want to reference (Pages 179 - 183) Section 5.5 while completing this problem.Calculate the energy needed for this temperature change.        
The specific heat of octane, C8H18 (l), is 2.22 J/g K.How many J of heat are needed to raise the temperature of 82.0 g of octane from 11.2 oC to 25.2 oC?
A 100.0-g bar of gold is heated from 25 oC to 50 oC, during which it absorbs 322 J of heat. Assume the volume of the gold bar remains constant. You may want to reference (Pages 179 - 183) Section 5.5 while completing this problem.Based on the data, calculate the specific heat of Au (s).
A 100.0-g bar of gold is heated from 25 oC to 50 oC, during which it absorbs 322 J of heat. Assume the volume of the gold bar remains constant. You may want to reference (Pages 179 - 183) Section 5.5 while completing this problem.What is the molar heat capacity of Au (s) ?
You may want to reference(Pages 259 - 264)section 6.4 while completing this problem.How much heat is required to warm 1.50 kg of sand from 26.0 oC to 100.0 oC?        
A coffee-cup calorimeter contains 150.0 g of water at 25.2 oC . A 123.0-g block of copper metal is heated to 100.4 oC by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.2 oC .Determine the amount of heat, in J, lost by the copper block.
A coffee-cup calorimeter contains 150.0 g of water at 25.2 oC . A 123.0-g block of copper metal is heated to 100.4 oC by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.2 oC .Determine the amount of heat gained by the water. The specific heat of water is 4.18 J/g.
5.00 moles of an ideal gas are contained in a cylinder with a constant external pressure of 1.00 atm and at a temperature of 593 K by a movable, frictionless piston. This system is cooled to 504 K.i) Calculate the work done on or by the system.   ii) Given that the molar heat capacity (C) of an ideal gas is 20.8 J/mol K, calculate q (J), the heat that flows into or out of the system. 
Liquid sodium is being considered as an engine coolant. How many grams of liquid sodium (minimum) are needed to absorb 3.10 MJ of energy (in the form of heat) if the temperature of the sodium is not to increase by more than 10.0. Use Cm = 30.8 J/(K·mol) for Na(l).
Which will release more heat as it cools from 50°C to 25°C, 1 kg of water or 1 kg of aluminum? How do you know? 
A sample of copper absorbs 43.6 kJ of heat, resulting in a temperature rise of 75°C, determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J/g°C. A) 6.62 kg B) 1.51 kg C) 3.64 kg D) 7.94 kg E) 1.26 kg
If you have 340.0 mL of water at 25.00 °C and add 120.0 mL of water at 95.00 °C, what is the final temperature of the mixture? Use 1.00 g/mL as the density of water.
Determine the specific heat capacity of an alloy that requires 59.3 kJ to raise the temperature of 150.0 g alloy from 298 K to 398 K. A) 4.38 J/g°C B) 3.95 J/g°C C) 2.29 J/g°C D) 1.87 J/g°C E) 2.53 J/g°C
Calculate the amount of heat (in kJ) necessary to raise the temperature of 47.8 g benzene by 57 K. The specific heat capacity of benzene is 1.05 J/g°C A) 2.59 kJ B) 2.86 kJ C) 3.85 kJ D) 1.61 kJ E) 16.6 kJ  
Calculate the amount of heat (in kJ) required to raise the temperature of a 79.0 g sample of ethanol from 298 K to 385 K. The specific heat capacity of ethanol is 2.42 J/g°C. A) 12.9 kJ B) 57.0 kJ C) 73.6 kJ D) 28.4 kJ E) 16.6 kJ  
How much heat, in kJ, is required to raise the temperature of 125 g H 2O from 24.3°C to 64.9°C? The specific heat of water is 4.18 J g-1 °C-1. A) 21.2 kJ B) 42.4 kJ C) 12.7 kJ D) 33.9 kJ E) 523 kJ  
A house is designed to have passive solar energy features. Brickwork incorporated into the interior of the house acts as a heat absorber. Each brick weighs approximately 1.8 kg. The specific heat of the brick is 0.85 J/g-K. How many bricks must be incorporated into the interior of the house to provide the same total heat capacity as 1.7 x 103 gal of water?
A coffee-cup calorimeter of the type shown in Figure 5.17 contains 150.0 g of water at 25.1°C. A 121.0-g block of copper metal is heated to 100.4°C by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g•K. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.1°C. (a) Determine the amount of heat, in J, lost by the copper block. 
A coffee-cup calorimeter of the type shown in Figure 5.17 contains 150.0 g of water at 25.1°C. A 121.0-g block of copper metal is heated to 100.4°C by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g•K. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.1°C. (b) Determine the amount of heat gained by the water. The specific heat of water is 4.18 J/g•K.
A coffee-cup calorimeter of the type shown in Figure 5.17 contains 150.0 g of water at 25.1°C. A 121.0-g block of copper metal is heated to 100.4°C by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g•K. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.1°C. (c) The difference between your answers for (a) and (b) is due to heat loss through the Styrofoam® cups and the heat necessary to raise the temperature of the inner wall of the apparatus. The heat capacity of the calorimeter is the amount of heat necessary to raise the temperature of the apparatus (the cups and the stopper) by 1 K. Calculate the heat capacity of the calorimeter in J/K.
A coffee-cup calorimeter of the type shown in Figure 5.17 contains 150.0 g of water at 25.1°C. A 121.0-g block of copper metal is heated to 100.4°C by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g•K. The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.1°C. (d) What would be the final temperature of the system if all the heat lost by the copper block were absorbed by the water in the calorimeter?
To raise 232 g of an unknown liquid from 15°C to 60°C, 17.9 kJ of energy are required. What is the specific heat capacity, Cs, of the liquid? A) 5.41 J/(g ∙ °C)         B) 1.71 J/(g ∙ °C)         C) 3.48 J/(g ∙ °C)         D) 1.10 J/(g ∙ °C)
Which one of the following statements is correct?A) The SI unit of specific heat capacity is calories per gram (cal/g)B) Specific heat capacity is a positive value for liquids and a negative value for solidsC) When heat is transferred from the surrounding to the system q is negativeD) The larger the heat capacity of an object the more thermal energy it can storeE) Heat is transformed from the systems to the surroundings in an endothermic process
A sample of steam with a mass of 0.510 g and at a temperature of 100°C condenses into an insulated container holding 4.50 g of water at 2.0°C.( ΔH°vap = 40.7 kJ/mol, water = 4.18 J/g•°C) Assuming that no heat is lost to the surroundings, what is the final temperature of the mixture?
Sucrose (table sugar) has the formula C12H22O11 (molar mass = 342.30 g/mol) and a food value of 6.49 kJ/g. Determine the calorimeter constant of the calorimeter in which the combustion of 0.995 g of sucrose raises the temperature by 4.21 degrees celsius (answer must be in kJ/degrees celsius).
Suppose a 50.0 g block of silver (specific heat = 0.2350 J/g.°C.) at 100°C is placed in contact with a 50.0 g block of iron (specific heat = 0.4494 J/g.°C.) at 0°C, and the two blocks are insulated from the rest of the universe. The final temperature of the two blocks.a) will be higher than 50°C.b) will be lower than 50°C.c) will be exactly 50°C.d) is unrelated to the composition of the blocks.e) cannot be predicted.
What is the heat capacity of 155 g of liquid water?
NOTE: YOUR ANSWER SHOULD BE IN KJ/MolWhen 0.535 g of compound X is burned completely in a bomb calorimeter containing 3000 g of water, a temperature rise of 0.363◦C is observed. What is ∆Urxn for the combusion of compound X? The hardware component of the calorimeter has a heat capacity of 3.51 kJ/◦C. The specific heat of water is 4.184 J/g ·◦C, and the MW of X is 56.0 g/mol.1. -426.0662. -610.2963. -1074.214. -898.3525. -988.4256. -760.5147. -589.8938. -487.4289. -927.73110. -875.701
In a calorimetry experiment a student determines the enthalpy for the reaction of magnesium with hydrochloric acid to be -430 kJ/mol. The true enthalpy for this reaction is -450 kJ/mol. Which of the following sources of error could account for this discrepancy?a. After recording the mass, some of the magnesium was dropped on the counterb. Some of the hot hydrogen gas escaped during the reaction.c. The calorimeter was not tightly shut for the experiment.d. The final temperature was recorded before the reaction was complete.e. All of these errors would cause a falsely high value for the enthalpy
A bar of hot metal is placed in water in an insulated container and the two are allowed to reach thermal equilibrium. When 1.0 kg of metal at 100°C is placed in 2.0 kg of water, the temperature water bath raises from 20°C to 25°C. What is the specific heat capacity of the metal (J/g K)?a) 0.5b) 1.5c) 0.22d) 25e) 0.025
Two solid objects, A and B, are placed in boiling water and allowed to come to the temperature of the water. Each is then lifted out and placed in separate beakers containing 1000 g water at 10.0°C. Object A increases the water temperature by 3.50°C; B increases the water temperature by 2.60°C. (a) Which object has the larger heat capacity?
Given the following balanced equation,2 Na(s) + 2 H2O(l) → 2 NaOH(aq) + H2(g)               ∆Hrxn = −368.4 kJwhich statement(s) is/are True?     I) The reaction is endothermic.II) The heat associated for reacting 1 mole of H 2O(l) is −184.2 kJ.III) The temperature of the solution increases when the reaction is carried out in a coffee-cup calorimeter. A) I only      B) II only     C) III only         D) both I and II         E) both II and III
The specific heat of iron metal is 0.450 J/g-K. How many J of heat are necessary to raise the temperature of a 1.05-kg block of iron from 25.0°C to 88.5°C?
When a 9.55-g sample of solid sodium hydroxide dissolves in 100.0 g of water in a coffee-cup calorimeter (Figure 5.17), the temperature rises from 23.6°C to 47.4°C. Calculate ΔH (in kJ/mol NaOH) for the solution processNaOH(s) → Na+(aq) + OH–(aq)Assume that the specific heat of the solution is the same as that of pure water. 
A 2.200-g sample of quinone (C6H4O2) is burned in a bomb calorimeter whose total heat capacity is 7.854 kJ/°C. The temperature of the calorimeter increases from 23.44°C to 30.57°C. What is the heat of combustion per gram of quinone? Per mole of quinone?
Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from 15.4°C to 93.0°C. A) 0.027 J             B) 324 J             C) 389 J         D) 931 J         E) 3,890 J  
The two aqueous solutions are not at room temperature and are then mixed in a coffee cup calorimeter. The reaction causes the temperature of the resulting solution to fall below room temperature. Which of the following statements is TRUE? a. The products have a lower potential energy than the reactants.b. This type of experiment will provide data to calculate ΔE rxnc. The reaction is exothermic.d. Energy is leaving the system during the reaction.e. None of the above statements is true.
The specific heat of methanol is 2.5104 J/g.ºC. How many kJ are necessary to raise the temperature of 2.00 L of methanol from 14.0C to 30.0°C? The density of methanol is 0.7915 g/mL. 
A sample of calcium carbonate [CaCO3 (s)] absorbs 45.5 J of heat, upon which the temperature of the sample increases from 21.1oC to 28.5oC. If the specific heat of calcium carbonate is 0.82 J/goC, what is the mass (in grams) of the sample? A. 0.20 B. 5.0 C. 7.5 D. 410 e. 5.0 x 103
It takes 75.0 J to raise the temperature of an 19.3 g piece of unknown metal from 21.0oC to 46.7oC. What is the specific heat of the metal? 
A 2.78g lead weight, initially at 11.0°C, is submerged in 7.66g of water at 52.3°C in an insulated container. What is the final temperature of both the weight and the water at thermal equilibrium?
Explain the difference between heat capacity and specific heat of a substance.
A kilogram of aluminum metal and a kilogram of water are each warmed to 75 oC and placed in two identical insulated containers. One hour later, the two containers are opened and the temperature of each substance is measured. The aluminum has cooled to 35 oC while the water has cooled only to 66 oC. Explain this difference.
Diluting sulfuric acid with water is highly exothermic:H2SO4(l)     H2O ⟶ H2SO4(aq) + heatUse the ideas of density and heat capacity to explain why you should add acid to water rather than water to acid.
Would the amount of heat absorbed by the dissolution in Example 5.6 appear greater, lesser, or remain the same if the heat capacity of the calorimeter were taken into account? Explain your answer.
Both propane and butane are used as gaseous fuels. Which compound produces more heat per gram when burned?
A 1-kg cylinder of aluminum and 1-kg jug of water, both at room temperature, are put into a refrigerator. After one hour, the temperature of each object is measured. One of the objects is much cooler than the other. Which one?
Two substances A and B, initially at different temperatures, are thermally isolated from their surroundings and allowed to come into thermal contact. The mass of substance A is twice the mass of substance B, but the specific heat capacity of substance B is four times the specific heat capacity of substance A. Which substance will undergo a larger change in temperature?
Four 50.0-g samples of different colorless liquids are placed in beakers at Tinitial = 25.0°C. Each liquid is heated until 450.0 J of heat has been absorbed; Tfinal is shown on each beaker below. Rank the liquids in order of increasing specific heat capacity.
Suppose you are cold-weather camping and decide to heat some objects to bring into your sleeping bag for added warmth. You place a large water jug and a rock of equal mass near the fire. Over time, both the rock and the water jug warm to about 38 oC (100 oF). If you could bring only one into your sleeping bag, which one should you choose to keep you the warmest?
The specific heat of water is 4.184 J/g °c and that of aluminum is .89 J/g °c. Will 1 gram of water or 1 gram of aluminum have the biggest increase in temperature upon the addition of 4.184 J? Explain.
Consider the following reaction.2 HCl(aq) + Ba(OH)2(aq) → BaCl2(aq) + 2H2O(l)       ΔH = -118 kJCalculate the heat when 102.4 mL of 0.500 M HCl is mixed with 300.0 mL of 0.410 M Ba(OH)  2. Assuming that the temperature of both solutions was initially 25.0°C and that the final mixture has a mass of 402.4 g and a specific heat capacity of 4.18J/°C·g, calculate the final temperature of the mixture.
What is the change in enthalpy (∆H) for a chemical reaction?
How is ∆H different from ∆E?
If a student performs an endothermic reaction in a calorimeter, how does the calculated value of ΔH differ from the actual value if the heat exchanged with the calorimeter is not taken into account?
Exactly 1.5 g of a fuel is burned under conditions of constant pressure and then again under conditions of constant volume. In measurement A the reaction produces 25.9 kJ of heat, and in measurement B the reaction produces 23.3 kJ of heat. Which measurement (A or B) corresponds to conditions of constant pressure?
Exactly 1.5 g of a fuel is burned under conditions of constant pressure and then again under conditions of constant volume. In measurement A the reaction produces 25.9 kJ of heat, and in measurement B the reaction produces 23.3 kJ of heat. Which one corresponds to conditions of constant volume?
Calculate DH8 for each of the following reactions using the data in Appendix 4:4Na (s) + O2 (g) → 2Na2O (s)2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g)2Na (s) + CO2 (g) → Na2O (s) + CO (g)Explain why a water or carbon dioxide fire extinguisher might not be effective in putting out a sodium fire.
Write a balanced equation and draw an enthalpy diagram for combustion of 1 mol of ethane.
Write a balanced equation and draw an enthalpy diagram for freezing of liquid water.
Would the amount of heat measured for the reaction HCl(aq) + NaOH(aq) ⟶ NaCl(aq) + H 2O(l)be greater, lesser, or remain the same if we used a calorimeter that was a poorer insulator than a coffee cup calorimeter? Explain your answer.
Would the amount of heat absorbed by the dissolution in Example 5.6 appear greater, lesser, or remain the same if the experimenter used a calorimeter that was a poorer insulator than a coffee cup calorimeter? Explain your answer.
A 500 mL bottle of water at room temperature and a 2 L bottle of water at the same temperature were placed in a refrigerator. After 30 minutes, the 500 mL bottle of water had cooled to the temperature of the refrigerator. An hour later, the 2 L of water had cooled to the same temperature. When asked which sample of water lost the most heat, one student replied that both bottles lost the same amount of heat because they started at the same temperature and finished at the same temperature. A second student thought that the 2 L bottle of water lost more heat because there was more water. A third student believed that the 500 mL bottle of water lost more heat because it cooled more quickly. A fourth student thought that it was not possible to tell because we do not know the initial temperature and the final temperature of the water. Indicate which of these answers is correct and describe the error in each of the other answers.
One of the components of polluted air is NO. It is formed in the high-temperature environment of internal combustion engines by the following reaction:N2 (g) + O2 (g) → 2NO (g),  ΔH = 180 kJWhy are high temperatures needed to convert N2 and O2 to NO?
The reactionSO3 (g) + H2O (l) → H2SO4(aq)is the last step in the commercial production of sulfuric acid. The enthalpy change for this reaction is -227 kJ. In designing a sulfuric acid plant, is it necessary to provide for heating or cooling of the reaction mixture? Explain.
A 45 g aluminum spoon (specific heat 0.88 J/g°C) at 24°C is placed in 180 mL (180 g) of coffee at 85°C and the temperature of the two become equal.The first time a student solved this problem she got an answer of 88°C. Explain why this is clearly an incorrect answer.
How many kJ of heat are needed to raise the temperature of 11.00 kg of liquid water from 24.6 ∘C to 46.5 ∘C?
a. What is the specific heat of liquid water? b. What is the molar heat capacity of liquid water? c. What is the heat capacity of 185 g of liquid water? d. How many k J of heat are needed to raise the temperature of 10.00 kg of liquid water from 24.6° C to 46.2°C?  
At 1 atm, how much energy is required to heat 55.0g of H2O(s) at -22.0°C to H2O(g) at 123.0°C? Answer in kJ and explain in detail.
You may want to reference (Pages 265 - 266) Section 6.5 while completing this problem.When 1.551 g of liquid hexane (C6H14) undergoes combustion in a bomb calorimeter, the temperature rises from 25.76 oC to 38.51 oC. Find ∆Erxn for the reaction in kJ/mol hexane. The heat capacity of the bomb calorimeter, determined in a separate experiment, is 5.75 kJ/oC .
Which is the least expensive source of energy in kilojoules per dollar: a box of breakfast cereal that weighs 32 ounces and costs $4.23, or a liter of isooctane (density, 0.6919 g/mL) that costs $0.45? Compare the nutritional value of the cereal with the heat produced by combustion of the isooctane under standard conditions. A 1.0 ounce serving of the cereal provides 130 Calories.
Explain how the heat measured in Example 5.5 differs from the enthalpy change for the exothermic reaction described by the following equation:HCl(aq) + NaOH(aq) ⟶ NaCl(aq) + H 2O(l)
Using the data in the check your learning section of Example 5.5, calculate ΔH in kJ/mol of AgNO3(aq) for the reaction: NaCl(aq) + AgNO3(aq) ⟶ AgCl(s) + NaNO 3(aq)
Calculate the enthalpy of solution (ΔH for the dissolution) per mole of NH 4NO3 under the conditions described in Example 5.6.
A coffee-cup calorimeter initially contains 125 g water at 24.2°C. Potassium bromide (10.5 g), also at 24.2°C, is added to the water, and after the KBr dissolves, the final temperature is 21.1°C. Calculate the enthalpy change for dissolving the salt in J/g and kJ/mol. Assume that the specific heat capacity of the solution is 4.18 J/°C ? g and that no heat is transferred to the surroundings or to the calorimeter.
In a coffee-cup calorimeter, 1.60 g NH4NO3 is mixed with 75.0 g water at an initial temperature of 25.00°C. After dissolution of the salt, the final temperature of the calorimeter contents is 23.34°C. Assuming the solution has a heat capacity of 4.18 J/°C ? g and assuming no heat loss to the calorimeter, calculate the enthalpy change for the dissolution of NH4NO3 in units of kJ/mol.
Consider the reaction2ClF3 (g) +  2NH3 (g) → N2 (g) + 6HF(g) + Cl2 (g)ΔH° = -1196 kJCalculate ΔHf° for ClF3(g).
Quinone is an important type of molecule that is involved in photosynthesis. The transport of electrons mediated by quinone in certain enzymes allows plants to take water, carbon dioxide, and the energy of sunlight to create glucose. A 0.1964-g sample of quinone (C6H4O2) is burned in a bomb calorimeter with a heat capacity of 1.56 kJ/°C. The temperature of the calorimeter increases by 3.2°C. Calculate the energy of combustion of quinone per gram and per mole.
Syngas can be burned directly or converted to methanol. Calculate ΔH° for the reactionCO (g) + 2 H2 (g) → CH3OH (l)
Ethanol (C2H5OH) has been proposed as an alternative fuel. Calculate the standard enthalpy of combustion per gram of liquid ethanol.
Methanol (CH3OH) has also been proposed as an alternative fuel. Calculate the standard enthalpy of combustion per gram of liquid methanol, and compare this answer to that for ethanol in Exercise 87.
Consider the reactionB2H6 (g) + 3O2 (g) → B2O3 (s) + 3H2O (g)            ΔH = -2035 kJCalculate the amount of heat released when 54.0 g of diborane is combusted.
The heat of vaporization of water at 373 K is 40.7 kJ/mol. Find ΔE for the evaporation of 451 g of water at this temperature.
The heat of vaporization of water at 373 K is 40.7 kJ/mol. Find ΔH for the evaporation of 451 g of water at this temperature.
Find ΔE for the change in state of 1.0 mol H2O(l) at 81 oC to H2O(g) at 115 oC. The heat capacity of H2O(l) = 75.3 J/mol K, heat capacity of H2O(g) = 25.0 J/mol K, and the heat of vaporization of H2O is 40.7 103/mol at 100 oC.
Find ΔH for the change in state of 1.0 mol H2O(l) at 81 oC to H2O(g) at 115 oC. The heat capacity of H2O(l) = 75.3 J/mol K, heat capacity of H2O(g) = 25.0 J/mol K, and the heat of vaporization of H2O is 40.7 103/mol at 100 oC.
The heat of combustion of liquid octane (C8H18) to carbon dioxide and liquid water at 298 K is -1303 kJ/mol. Find ΔE for this reaction.
When a 3.80-g sample of liquid octane (C8H18) is burned in a bomb calorimeter, the temperature of the calorimeter rises by 27.1 °C. The heat capacity of the calorimeter, measured in a separate experiment, is 6.21 kJ/°C. Determine ΔE for octane combustion in units of kJ/mol octane.
Mothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 1.025 g of naphthalene is burned in a bomb calorimeter, the temperature rises from 24.25°C to 32.33°C. Find ΔErxn for the combustion of naphthalene. The heat capacity of the calorimeter, determined in a separate experiment, is 5.11 kJ/°C.
What is the molar heat capacity of liquid water? Express your answer using four significant figures.
Two substances, lead and glass (Pyrex), initially at different temperatures, come into contact and reach thermal equilibrium. The mass of lead is 18.1 g and its initial temperature is 62.6˚C. The mass of glass (Pyrex) is 20.6 g and its initial temperature is 25.1˚C. What is the final temperature of both substances at thermal equilibrium? (The specific heat capacity of lead is 0.128 J/g•˚C; the specific heat capacity of glass (Pyrex) is 0.75 J/g•˚C.)
A 4.96 g sample of gold, initially at 62.6˚C, is submerged into 55.1 g of ethanol at 20.1˚C in an insulated container. What is the final temperature of both substances at thermal equilibrium? (The specific heat capacity of gold is 0.128 J/g•˚C; the specific heat capacity of ethanol is 2.42 J/g•˚C)
You may want to reference (Pages 259 - 264) Section 6.4 while completing this problem.A 32.6 g iron rod, initially at 22.3 oC, is submerged into an unknown mass of water at 63.3 oC, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 59.1 oC.What is the mass of the water?
A 30.0-g sample of water at 280. K is mixed with 50.0 g water at 330. K. Calculate the final temperature of the mixture assuming no heat loss to the surroundings.
How many milliliters of water at 23°C with a density of 1.00 g/mL must be mixed with 180 mL (about 6 oz) of coffee at 95°C so that the resulting combination will have a temperature of 60°C? Assume that coffee and water have the same density and the same specific heat.
How much will the temperature of a cup (180 g) of coffee at 95°C be reduced when a 45 g silver spoon (specific heat 0.24 J/g°C) at 25°C is placed in the coffee and the two are allowed to reach the same temperature? Assume that the coffee has the same density and specific heat as water.
A pure gold ring and pure silver ring have a total mass of 16.0 g. The two rings are heated to 71.1 oC and dropped into a 13.6 mL of water at 21.8 oC. When equilibrium is reached, the temperature of the water is 24.2 oC. What is the mass of gold ring? (Assume a density of 0.998 g/mL for water.)
A pure gold ring and pure silver ring have a total mass of 16.0 g. The two rings are heated to 71.1 oC and dropped into a 13.6 mL of water at 21.8 oC. When equilibrium is reached, the temperature of the water is 24.2 oC. What is the mass of silver ring? (Assume a density of 0.998 g/mL for water.)
Two iron bolts of equal mass—one at 100.°C, the other at 55°C—are placed in an insulated container. Assuming the heat capacity of the container is negligible, what is the final temperature inside the container (c of iron = 0.450 J/g•K)?
One piece of copper jewelry at 105°C has twice the mass of another piece at 45°C. Both are placed in a calorimeter of negligible heat capacity. What is the final temperature inside the calorimeter (c of copper = 0.387 J/g•K)?
When 155 mL of water at 26°C is mixed with 75 mL of water at 85°C, what is the final temperature? (Assume that no heat is released to the surroundings; d of water = 1.00 g/mL.)
A biology experiment requires the preparation of a water bath at 37.0°C (body temperature). The temperature of the cold tap water is 22.0°C, and the temperature of the hot tap water is 55.0°C. If a student starts with 90.0 g cold water, what mass of hot water must be added to reach 37.0°C?
(a) How much heat is released when 25.0 g of methane burns in excess O2 to form gaseous CO2 and H2O? (b) Calculate the temperature of the product mixture if the methane and air are both at an initial temperature of 0.0°C. Assume a stoichiometric ratio of methane to oxygen from the air, with air being 21% O2 by volume (c of CO 2 = 57.2 J/mol•K; c of H 2O(g) = 36.0 J/mol•K; c of N 2 = 30.5 J/mol•K).
A 45 g aluminum spoon (specific heat 0.88 J/g°C) at 24°C is placed in 180 mL (180 g) of coffee at 85°C and the temperature of the two become equal.What is the final temperature when the two become equal? Assume that coffee has the same specific heat as water.
A 5.00-g sample of aluminum pellets (specific heat capacity = 0.89 J/°C ? g) and a 10.00-g sample of iron pellets (specific heat capacity = 0.45 J/°C ? g) are heated to 100.0°C. The mixture of hot iron and aluminum is then dropped into 97.3 g water at 22.0°C. Calculate the final temperature of the metal and water mixture, assuming no heat loss to the surroundings.
The specific heat of water is 4.18 J/(g • °C). Calculate the molar heat capacity of water. A volume of 115 mL of H2O is initially at room temperature (22.00 °C). A chilled steel rod at 2.00 °C is placed in the water. If the final temperature of the system is 21.10 °C , what is the mass of the steel bar? Specific heat of water = 4.18 J/(g • °C) specific heat of steel = 0.452 J/(g • °C).
A 150.0-g sample of a metal at 75.0°C is added to 150.0 g H2O at 15.0°C. The temperature of the water rises to 18.3°C. Calculate the specific heat capacity of the metal, assuming that all the heat lost by the metal is gained by the water.
A 70.0 g piece of metal at 80.0°C is placed in 100 g of water at 22.0°C contained in a calorimeter like that shown in Figure 5.12. The metal and water come to the same temperature at 24.6°C. How much heat did the metal give up to the water? What is the specific heat of the metal?
A 110.-g sample of copper (specific heat capacity 5 0.20 J/°C ? g) is heated to 82.4°C and then placed in a container of water at 22.3°C. The final temperature of the water and copper is 24.9°C. What is the mass of the water in the container, assuming that all the heat lost by the copper is gained by the water?
You may want to reference (Page 260) Section 6.4 while completing this problem.A 13.0 g sample of granite initially at 82.0 oC is immersed into 26.0 g of water initially at 23.0 oC. What is the final temperature of both substances when they reach thermal equilibrium? (For water, Cs =4.18 J/g•oC and for granite, Cs =0.790 J/g•oC.)
A 2.78g lead weight, initially at 11.0°C, is submerged in 7.66g of water at 52.3°C in an insulated container. What is the final temperature of both the weight and the water at thermal equilibrium?
You may want to reference (Pages 259 - 264)Section 6.4 while completing this problem.A 2.51 g lead weight, initially at 10.6˚C, is submerged in 7.86 g of water at 52.4˚C in an insulated container. What is the final temperature of both the weight and the water at thermal equilibrium?
One method of generating electricity is by burning coal to heat water, which produces steam that drives an electric generator. To determine the rate at which coal is to be fed into the burner in this type of plant, the heat of combustion per ton of coal must be determined using a bomb calorimeter. When 1.00 g of coal is burned in a bomb calorimeter (Figure 5.17), the temperature increases by 1.48°C. If the heat capacity of the calorimeter is 21.6 kJ/°C, determine the heat produced by combustion of a ton of coal (2.000 x 103 pounds).
An unknown mass of each substance, initially at 24.0˚C, absorbs 1950 J of heat. The final temperature is recorded. Find the mass of each substance: Pyrex glass (Tf = 55.5˚C)
An unknown mass of each substance, initially at 24.0˚C, absorbs 1950 J of heat. The final temperature is recorded. Find the mass of each substance: sand (Tf = 62.2˚C)
An unknown mass of each substance, initially at 24.0˚C, absorbs 1950 J of heat. The final temperature is recorded. Find the mass of each substance: ethanol (Tf = 44.3˚C)
An unknown mass of each substance, initially at 24.0˚C, absorbs 1950 J of heat. The final temperature is recorded. Find the mass of each substance: water (Tf = 32.2˚C)
Consider the substances in Table 7‑1. Which substance requires the largest amount of energy to raise the temperature of 25.0 g of the substance from 15.0°C to 37.0°C? Calculate the energy. Which substance in Table 7‑1 has the largest temperature change when 550. g of the substance absorbs 10.7 kJ of energy? Calculate the temperature change.
The specific heat capacity of silver is 0.24 J/°C•ga. Calculate the energy required to raise the temperature of 150.0 g Ag from 273 K to 298 K.
SubstanceSpecific heatcapacity, Cs (J/(g oC))*ElementsLead0.128Gold0.128Silver0.235Copper0.385Iron0.449Aluminum0.903CompoundsEthanol2.42Water4.18MaterialsGlass (Pyrex)0.75Granite0.79Sand0.84* At 298 K.A 51 g aluminum block initially at 27.0 oC absorbs 737 J of heat. What is the final temperature of the aluminum?
In a bomb calorimeter, the reaction vessel is surrounded by water that must be added for each experiment. Since the amount of water is not constant from experiment to experiment, the mass of water must be measured in each case. The heat capacity of the calorimeter is broken down into two parts: the water and the calorimeter components. If a calorimeter contains 1.00 kg water and has a total heat capacity of 10.84 kJ/°C, what is the heat capacity of the calorimeter components?
The bomb calorimeter in Exercise 102 is filled with 987 g water. The initial temperature of the calorimeter contents is 23.32°C. A 1.056-g sample of benzoic acid (ΔEcomb = -26.42 kJ/g) is combusted in the calorimeter. What is the final temperature of the calorimeter contents?
Calculate the heat capacity, in joules and in calories per degree, of the following: 28.4 g of water
Calculate the heat capacity, in joules and in calories per degree, of the following: 1.00 oz of lead
Calculate the heat capacity, in joules and in calories per degree, of the following:45.8 g of nitrogen gas
Calculate the heat capacity, in joules and in calories per degree, of the following:1.00 pound of aluminum metal
How much heat, in joules and in calories, must be added to a 75.0 g iron block with a specific heat of 0.449 J/g°C to increase its temperature from 25°C to its melting temperature of 1535°C?
How much heat, in joules and in calories, is required to heat a 28.4 g (1 oz) ice cube from −23.0°C to −1.0°C?
How much would the temperature of 275 g of water increase if 36.5 kJ of heat were added?
The specific heat capacity of silver is 0.24 J/°C•gb. Calculate the energy required to raise the temperature of 1.0 mole of Ag by 1.0°C (called the molar heat capacity of silver).
If 14.5 kJ of heat were added to 485 g of liquid water, how much would its temperature increase?
Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. It is used to make cosmetics, ointments, soaps, and candles and is found in animal tissue as part of many saturated fats. In fact, when you eat meat, you are ingesting some fats containing stearic acid.Calculate the heat (q) released in kJ and kcal when 1.00 g of stearic acid is burned completely.
A piece of unknown substance weighs 44.7 g and requires 2110 J to increase its temperature from 23.2°C to 89.6°C.What is the specific heat of the substance?
The specific heat capacity of silver is 0.24 J/°C•gc. It takes 1.25 kJ of energy to heat a sample of pure silver from 12.0°C to 15.2°C. Calculate the mass of the sample of silver.
A piece of unknown substance weighs 44.7 g and requires 2110 J to increase its temperature from 23.2°C to 89.6°C.If it is one of the substances found in Table 5.1, what is its likely identity?
A piece of unknown solid substance weighs 437.2 g, and requires 8460 J to increase its temperature from 19.3°C to 68.9°C.What is the specific heat of the substance?
The combustion of 0.1584 g benzoic acid increases the temperature of a bomb calorimeter by 2.54°C. Calculate the heat capacity of this calorimeter. (The energy released by combustion of benzoic acid is 26.42 kJ/g.) A 0.2130-g sample of vanillin (C8H8O3) is then burned in the same calorimeter, and the temperature increases by 3.25°C. What is the energy of combustion per gram of vanillin? Per mole of vanillin?
A piece of unknown solid substance weighs 437.2 g, and requires 8460 J to increase its temperature from 19.3°C to 68.9°C.If it is one of the substances found in Table 5.1, what is its likely identity?
An aluminum kettle weighs 1.05 kg.What is the heat capacity of the kettle?
A 5.00-g sample of one of the substances listed in Table 7‑1 was heated from 25.2°C to 55.1°C, requiring 133 J to do so. Which substance was it?
An aluminum kettle weighs 1.05 kg.How much heat is required to increase the temperature of this kettle from 23.0°C to 99.0°C?
An aluminum kettle weighs 1.05 kg.How much heat is required to heat this kettle from 23.0°C to 99.0°C if it contains 1.25 L of water (density of 0.997 g/mL and a specific heat of 4.184 J/g°C)?
It takes 585 J of energy to raise the temperature of 125.6 g mercury from 20.0°C to 53.5°C. Calculate the specific heat capacity and the molar heat capacity of mercury.
Evaporating sweat cools the body because evaporation is an endothermic process: H2O(l) → H2O(g); ΔH˚rxn= + 44.01 kJ. Estimate the mass of water that must evaporate from the skin to cool the body by 0.55˚C. Assume a body mass of 95 kg and assume that the specific heat capacity of the body is 4.0 J/g•˚C.
A sample of nickel is heated to 99.8°C and placed in a coffeecup calorimeter containing 150.0 g water at 23.5°C. After the metal cools, the final temperature of metal and water mixture is 25.0°C. If the specific heat capacity of nickel is 0.444 J/°C ? g, what mass of nickel was originally heated? Assume no heat loss to the surroundings.
Liquid sodium is being considered as an engine coolant. How many grams of liquid sodium (minimum) are needed to absorb 5.90 MJ of energy (in the form of heat) if the temperature of the sodium is not increase by more than 10.0 degrees Celsius? Use Cp=30.8J/(K*mol) for Na(l) at 500K.
Find q when 22.0 g of water is heated from 25.0°C to 100.0°C.
Calculate q when 0.10 g of ice is cooled from 10.0°C to −75.0°C (c  ice = 2.087 J/g•K).
A 295-g aluminum engine part at an initial temperature of 13.00°C absorbs 75.0 kJ of heat. What is the final temperature of the part (c of Al = 0.900 J/g•K)?
A 27.7-g sample of the radiator coolant ethylene glycol releases 688 J of heat. What was the initial temperature of the sample if the final temperature is 32.5°C (c of ethylene glycol = 2.42 J/g•K)?
An unknown volume of water at 18.2°C is added to 24.4 mL of water at 35.0°C. If the final temperature is 23.5°C, what was the unknown volume? (Assume that no heat is released to the surroundings; d of water = 1.00 g/mL.)
A 455-g piece of copper tubing is heated to 89.5°C and placed in an insulated vessel containing 159 g of water at 22.8°C. Assuming no loss of water and a heat capacity of 10.0 J/K for the vessel, what is the final temperature (c of copper = 0.387 J/g·K)?
A swimming pool, 10.0 m by 4.0 m, is filled with water to a depth of 3.0 m at a temperature of 20.2°C. How much energy is required to raise the temperature of the water to 24.6°C?
Find q for the change in state of 1.0 mol H2O(l) at 81 oC to H2O(g) at 115 oC. The heat capacity of H2O(l) = 75.3 J/mol K, heat capacity of H2O(g) = 25.0 J/mol K, and the heat of vaporization of H2O is 40.7 103/mol at 100 oC.
Find w for the change in state of 1.0 mol H2O(l) at 81 oC to H2O(g) at 115 oC. The heat capacity of H2O(l) = 75.3 J/mol K, heat capacity of H2O(g) = 25.0 J/mol K, and the heat of vaporization of H2O is 40.7 103/mol at 100 oC.
The temperature of the cooling water as it leaves the hot engine of an automobile is 240°F. After it passes through the radiator it has a temperature of 175°F. Calculate the amount of heat transferred from the engine to the surroundings by one gallon of water with a specific heat of 4.184 J/g°C.
Hydrogen gives off 120. J/g of energy when burned in oxygen, and methane gives off 50. J/g under the same circumstances. If a mixture of 5.0 g hydrogen and 10. g methane is burned, and the heat released is transferred to 50.0 g water at 25.0°C, what final temperature will be reached by the water?
If a reaction produces 1.506 kJ of heat, which is trapped in 30.0 g of water initially at 26.5°C in a calorimeter like that in Figure 5.12, what is the resulting temperature of the water?
Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the equation: CO2(s) → CO2(g). When dry ice is added to warm water, heat from the water causes the dry ice to sublime more quickly. The evaporating carbon dioxide produces a dense fog often used to create special effects. In a simple dry ice fog machine, dry ice is added to warm water in a Styrofoam cooler. The dry ice produces fog until it evaporates away, or until the water gets too cold to sublime the dry ice quickly enough. Suppose that a small Styrofoam cooler holds 15.0 L of water heated to 86˚C.Calculate the mass of dry ice that should be added to the water so that the dry ice completely sublimes away when the water reaches 23˚C. Assume no heat loss to the surroundings.
If the 3.21 g of NH 4NO3 in Example 5.6 were dissolved in 100.0 g of water under the same conditions, how much would the temperature change? Explain your answer.
When 1.0 g of fructose, C6H12O6(s), a sugar commonly found in fruits, is burned in oxygen in a bomb calorimeter, the temperature of the calorimeter increases by 1.58°C. If the heat capacity of the calorimeter and its contents is 9.90 kJ°C, what is q for this combustion?
When a 0.740 g sample of trinitrotoluene (TNT), C 7H5N2O6, is burned in a bomb calorimeter, the temperature increases from 23.4°C to 26.9°C. The heat capacity of the calorimeter is 534 J/°C, and it contains 675 mL of water. How much heat was produced by the combustion of the TNT sample?
A sample of 0.562 g of carbon is burned in oxygen in a bomb calorimeter, producing carbon dioxide. Assume both the reactants and products are under standard state conditions, and that the heat released is directly proportional to the enthalpy of combustion of graphite. The temperature of the calorimeter increases from 26.74°C to 27.93°C. What is the heat capacity of the calorimeter and its contents?
A calorimeter was used to measure the heat change when an ionic compound dissolves in water. The final mass of the contents of the calorimeter was 50.73 g and the change in temperature was 2.35 ºC.Calculate the heat change of the calorimeter contents, given that its specific heat is 4.10 J (g ºC).Calculate the heat change of the calorimeter.Calculate the heat change of the solution process.
A 2.90 g lead weight, initially at 11.1 ºC, is submerged in 7.64 g of water at 51.8 ºC in an insulated container. You may want to reference section 10.4 while completing this problem. What is the final temperature of both the weight and water at thermal equilibrium? Express the temperature in Celsius to three significant figures.
Exactly 132.6 J will raise the temperature of 10.0 g of a metal from 25.0  C to 60.0 ºC. What is the specific heat capacity of the metal?a. 0.379 J/g -Cb. 2.64 J/g - Cc. 23.2 J/g - Cd. 31.7 J/g -C e. none of these
The combustion of how many moles of ethane (C2H6) would be required to heat 884 g of water from 25.0 C to 98.0 C? (Assume liquid water is formed during the combustion.) 
A volume of 110 mL of H_2O is initially at room temperature (22 00 degree C) A chilled steel rod at 2 00 degree C is placed n the water. If the final temperature of the system is 21.10 degree C, what is the mass of the steel bar?Use the following values specific heat of water = 4.18 J/(g middot degree C) specific heal of steel = 0.452 J/(g middot degree C) Express your answer to three significant figures and include the appropriate units.
A 31.5 g water of pure gold initially at 69.3 degree C is submerged into 63.9 g of water at 27.6 degree C in an insulated container. What is the final temperature of both substances at thermal equilibrium?
When Karl Kaveman adds chilled grog to his new granite mug, he removes 10.9 kJ of energy from the mug. If it has a mass of 625 g and was at 25°C, what is its new temperature? Specific heat capacity of granite = 0.79 J/g • °C. A. 3 °C B. 14 °C C. 22 °C D. 47 °C E. None of these choices is correct.
The specific heat of a certain type of cooking oil is 1.75 J/(g • °C). How much heat energy is needed to raise the temperature of 2.02 kg of this oil from 23 °C to 191 °C?
Enter your answer in the provided box.A 479 g sample of water has an initial temperature of 19.0 °C. After 76.2 kJ of energy is added to the water sample, what will be its final temperature?
The specific heat of a certain type of metal is 0.128 J/(g • °C). What is the final temperature if 305 J of heat is added to 43.4 g of this metal initially at 20.0°C?
If 125 cal of heat is applied to a 60.0-g piece of copper at 22.0°C, what will the final temperature be? The specific heat of copper is 0.0920 cal/(g • °C). Express your answer with the appropriate units.
Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the following equation: CO2 (s) → CO2 (g). When dry ice is added to warm water, heat from the water causes the dry ice to sublime more quickly. The evaporating carbon dioxide produces a dense fog often used to create special effects. In a simple dry ice fog machine, dry ice is added to warm water in a Styrofoam cooler. The dry ice produces fog until it evaporates away, or until the water gets too cold to sublime the dry ice quickly enough. Suppose that a small Styrofoam cooler holds 15.0 liters of water heated to 83 °C. Part AUse standard enthalpies of formation to calculate the change in enthalpy for dry ice sublimation. (The ΔH°f for CO2 (s) is -427.4 kJ/mol). Express your answer using three significant figures. Part BCalculate the mass of dry ice that should be added to the water so that the dry ice completely sublimes away when the water reaches 18 °C. Assume no heat loss to the surroundings. Express your answer using two significant figures.
You may want to reference (3 pages 349-355) section 10.4 while completing this problem.An unknown mass of each of the following substances, initially at 23.0°C absorbs 1560 J of heat. The final temperature is recorded as indicated. Find the mass of each substance.Part Cethanol (Tf = 44.4°C)Express your answer using two significant figuresPart Cwater (Tf = 32.2°C)Express your answer using two significant figures
If the heat of combustion for a specific compound is -1010.0 kJ/mol and its molar mass is 34.13 g/mol, how many grams of this compound must you burn to release 642.10 kJ of heat?
An 80.0-gram sample of a gas was heated from 25°C to 225°C. During this process. 346 J of work was done by the system and its internal energy increased by 6565 J. What is the specific heat of the gas?
A 54.0 g block of an unknown metal is heated in a hot water bath to 100.0 C. When the block is placed in an insulated vessel containing 130.0 g of water at 25.0 C, the final temperature is 28.0 C. Determine the specific heat of the unknown metal. The Cs for water is 4.18 J/g-C.
Enter your answer in the provided box. A 595-g piece of copper tubing is heated to 89.5 C and placed in an insulated vessel containing 159 g of water at 22.8 C. Assuming no loss of water and a heat capacity for the vessel of 10.0 J/C, what is the final temperature of the system (c of copper = 0.387 J/g  C)? 
When a 2.331-g sample of a new organic material was combusted in a bomb calorimeter, the temperature of the calorimeter (and its contents) increased from 23.89  C to 28.30 C. If the heat capacity (calorimeter constant) of the calorimeter is 31.45 kJ/ C, what is the heat of combustion per gram of the material?
The heat capacity of an object indicates how much energy that object can absorb for a given increase in that Use the following values: object's temperature. In a system in which two objects of specific heat of water 4.18 J/(g.°C) different temperatures come into contact with one another, the warmer object will cool and the cooler object specific heat of steel 0.452 J/(g C) will warm up until the system is at a single equilibrium temperature.Note the difference between the terms molar heat capacity, which has units of J/(mo C), and specific heat, which has units of J/(g. C).A volume of 125 mL of H2O is initially at room temperature (22.00 C), A chilled steel rod at 2.00 C is placed in the water. If the final temperature of the system is 21.10C, what is the mass of the steel bar?The specific heat of water is 4.18 J/(g. C). Calculate the molar heat capacity of water.Express your answer to three significant figures and include the appropriate units.°
How much energy must be transferred to raise the temperature of a cup of coffee (250. mL) from 20.0 degree C (293.35 K) to 98.4 °C (371.55 K)? Assume that water and coffee have the same density (1.00 g/mL) and specific heat capacity (4 184 J/g •K).
Suppose you place 0.0300 g of magnesium chips in a coffee-cup calorimeter and then add 100 0 ml. of 1.00 M HCl. The reaction that occurs isMg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq)The temperature of the solution increases from 22.56 degree C (295.71 K) to 23.91 °C (297.06 K). What is the enthalpy change for the reaction per mole of Mg? Assume a specific heat capacity of the solution is 4.20 I/g • K and the density of the HCI solution is 1.00 g/mL. kJ/mol
A 428 g iron weight is added to 425 ml of water in a calorimeter at 22.6. The final temperature of the water was measured as 43.8. What was the initial temperature of the iron weight (assuming a perfectly insulated calorimeter)? You may omit units since the degree symbol cannot be included. The specific heat of iron is 0.449 J/(g * °C) and that of water is 4,184 J/(g ° C).
A piece of cobalt with a mass of 4.28 grams is heated to raise its temperature from 22.1°C to 225.7°C. (a) What quantity of heat (in joules) is absorbed by the cobalt? (b) Determine the molar heat capacity of cobalt.
The propane fuel (C3H8) used in gas barbeques buns according to the following thermochemical equation: C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g)    ΔH°rxn = -2217kJ If a pork roast must absorb 1600 kJ to fully cook, and if only 12% of the heat produced by the barbeque is actually absorbed by the roast, what mass of CO2 is emitted into the atmosphere during the grilling of the pork roast? Express your answer using two significant figures.
A 129 g metal bar requires 2.50 kJ to change its temperature from 26.5°C to 100.0°C. What is the specific heat of the metal?Use correct number of significant digits, the tolerance is +/-1 in the 3rd significant digit.
Calculate the heat energy released when 11.9 g of liquid mercury at 25.00°C is converted to solid mercury at its melting point. 
Consider the following reaction. 2Fe2O3 → 4Fe + 3O2     ΔH°rxn = + 824.2 kJ The decomposition of 33.0 g of Fe2O3 results in (a) the release of 85.2 kJ of heat. (b) the release of 1.70 x 102 kJ of heat. (c) the absorption of 85.2 kJ of heat. (d) the absorption of 1.70 x 102 kJ of heat. (e) the absorption of 13600 kJ of heat. (f) the release of 13600 kJ of heat.
If you combine 280.0 mL of water at 25.00°C and 120.0 mL of water at 95.00°C, what is the final temperature of the mixture? Use 1.00 g/mL as the density of water. _____°C 
An ice cube of mass 8.5 g is added to a cup of coffee, whose temperature is 85 °C and which contains 130 g of liquid. Assume the specific heat capacity of the coffee is the same as that of water. The heat of fusion of ice (the heat associated with ice melting) is 6.0 kJ/mol. Part AFind the temperature of the coffee after the ice melts. Express your answer using two significant figures.
A 3.67-g peanut is burned in a bomb calorimeter containing 1,223 g of water. The temperature of the water increases from 22.01°C to 29.77°C. Calculate the energy released per gram of peanut. (The specific heat of water is 1.000 cal/g•°C.)
The complete combustion of 0. 731g of a snack bar in a calorimeter (C cal = 6.15 kJ/°C) raises the temperature of the calorimeter by 1.47°C. Calculate the food value (in Cal/g) for the snack bar.
The specific heat of a certain type of metal is 0.128 J/(g•°C). What is the final temperature if 305 J of heat is added to 41.4 g of this metal initially at 20.0°C?
A 29.75 g piece of iron and a 23.40 g piece of gold at 100.0 °C were dropped into 510.0 mL of water at 26.70 °C. The molar heat capacities of iron and gold are 25.19 J/(mol • °C) and 25.41 J/(mol • °C), respectively. What is the final temperature of the water and pieces of metal?
A 15.99 g sample of metal heated in a test tube submerged in 100.00°C water. It was then placed directly into a coffee cup calorimeter holding 51.95 g of water at 22.10°C. The temperature of the water increased to 24.99°C, determine the specific heat capacity of the metal. If the calorimete had absorbed 197.3 J and we factored that quantity into our calculation, what would the specific heat of the metal been?
If the heat of combustion for a specific compound is -1040.0 kJ/mol and its molar mass is 73.87 g/mol, how many grams of this compound must you burn to release 176.60 kJ of heat?
A hot lump of 106.2 g of an unknown substance initially at 153.2°C is placed in 35.0 mL of water initially at 25.0°C and allowed to reach thermal equilibrium. The final temperature of the system is 53.2°C. What is the identity of the unknown substance? Assume no heat is lost to the surroundings.
In a constant-pressure calorimeter, 70.0 mL of 0.840 M H2S04 was added to 70.0 mL of 0.460 M NaOH. The reaction caused the temperature of the solution to nse for 24.38°C - to 27.51°C. If the solution has the same density and specific heat as water (1.00 g/mL and 4.184 J/g • K, respectively), what is ΔH for this reaction (per mole of H2O produced)? Assume that the total volume is the sum of the individual volumes.
A 30.83 g sample of a substance is initially at 21.3°C. After absorbing 1733 J of heat, the temperature of the substance is 106.2°C. What is the specific heat (c) of the substance?
Exactly 10.3 mL of water at 31.0 °C are added to a hot iron skillet. All of the water is converted into steam at 100 °C. The mass of the pan is 1.15 kg and the molar heat capacity of iron is 25.19 J/(mol • °C). What is the temperature change of the skillet?
Liquid sodium is being considered as an engine coolant. How many grams of liquid sodium (minimum) are needed to absorb 4.30 MJ of energy (in the form of heat) if the temperature of the sodium is not to increase by more than 10.0°C? Use Cp = 30.8 J/(K • mol) for Na(l) at 500 K.
A 2.97 g lead weight, initially at 10.7 °C is submerged in 7.72 g of water at 52.9 °C in an insulated container.You may want to reference [(3) pages 256 - 262] section 6.4 while completing this product.What is the final temperature of both the weight and the water at thermal equilibrium? Express the temperature in Celsius to three significant figures.
A 49.3-g piece of metal is heated to 288 °C and dropped into 100.0 g of water at 12.0 °C. The metal and water come to the same temperature of 24.0 °C. What is the specific heat, in J/g °C, of the metal?
Two substances, A and B, initially at different temperature, come into contact and reach thermal equilibrium. The mass of substance A is 6.43 g and the initial temperature is 20.1°C. The mass of substance B is 25.0 g and the initial temperature is 52.1°C.  The final temperature of both substances at thermal equilibrium is 46.6°C.Part AIf the specitic heat capacity of substance B is 1.17 J/s°C, what is the specfic heat capacity of substance A? Express your answer using two significant figures.
Calculate the heat capacity of a calorimeter if the combustion of 5.000 g of benzoic acid led to a temperature increase of 16.573°C. The heat of combustion of benzoic acid is -26.38 kJ/g.
A 59.69 g sample of a substance is initially at 241°C. After absorbing 1197 J of heat, the temperature of is 169.5°C. What is the specific heat (c) of the substance?
The specific heat of a certain type of cooking of is 1.75 J/(g • °C). How much heat energy is needed to raise the temperature of 2.56 kg of this oil from 23°C to 191°C?
A 42.41 g sample of a substance is initially at 24.4°C. After absorbing 2839 J of heat the temperature of the substance is 191.3°C. What is the specific heat (SH) of the substance?
In the following experiment, a coffee-cup calorimeter containing 100 mL of H 2O is used. The initial temperature of the calorimeter is 23.0°C. If 9.50 g of CaCl2 is added to the calorimeter, what will be the final temperature of the solution in the calorimeter? The heat of solution ΔHsoln of CaCl2 is -82.8 kJ/mol. Express your answer with the appropriate units.
 The temperature of an object increases by 42.4°C when it absorbs 3833 J of heat. Calculate the heat of the object. The mass of the object is 377 g.Use this table of specific heats to identify the object.
The specific heat of a certain type of metal is 0.128 J/(g •°C). What is the final temperature if 305 J of heat is added to 63.7 g of this metal initially at 20.0°C.
A 34.22 g sample of a substance is initially at 282°C. After absorbing 2887 J of heat, the temperature of is 181.8°C. What is the specific heat (c) of the substance? 
A 285 g piece of granite, heated to 6.10 x 102 °C in a campfire, is dropped into 1.30 L water (d = 1.00 g/mL) at 25.0 °C. The molar heat capacity of water is cp, water = 75.3 J/(mol • °C), and the specific heat of granite is Cs, granite = 0.79 J/(g • °C). Calculate the final temperature of the granite.
Consider the following reaction: NaCl (s) → Na+ (aq) + Cl- (aq)         ΔH = 3.88 kJ/mol In a coffee-cup calorimeter you dissolve 21.9 g of this salt in 108 g of water at 27.7°C. What will be the final temperature of the solution formed? Assume the specific heat of the solution is 4.184 J/g°C, and that there is no heat loss to the surroundings. Please enter your answer to the correct number of significant figures.
You may want to reference ( pages 349-355) section 10.4 while comparing this problem.An unknown mass of each of the following substances, initially at 230°C, absorbs 1980 J of heat. The final temperature is recorded as indicated. Find the mass of each substancePart A a Pyrex glass (Tf = 553°C) Express your answer using two significant figures.  Part B sand (Tf = 621°C) Express your answer using two significant figures ○Type here to searo,
Four ice cubes at exactly 0°C with a total mass of 55.0 g are combined with 120 g of water at 85°C in an insulated container. (ΔHfun° = 6.02 kJ/mol, cwater = 4.18 J/g • °C) Part AIf no heat is lost to the surroundings, what is the final temperature of the mixture? Express your answer using two significant figures.
How much heat energy is required to raise the temperature of 0.358 kg of copper from 23.0°C to 60.0°C? The specific heat of copper is 0.0920 cal/(g • °C). Express your answer with the appropriate units.
The following equation is the balanced combustion reaction for C6H6: 2C6H6(l) + 15O2(g) → 12CO2(g) + 6H2O(l) + 6542 kJIf 8.800 g of C6H6 is burned and the heat produced from the burning is added to 5691 g of water at 21 °C, what is the final temperature of the water?
When a 6.50 g sample of solid sodium hydroxide dissolves in 100.0 g of water in a coffee-cup calorimeter (the following Figure), the temperature rises from 21.6°C to 37.8°C.Calculate ΔH (in kJ/mol NaOH) for the solution process NaOH(g) → Na+(aq) + OH-(aq) Assume that the specific heat of the solution is the same as that of pure water. Express your answer with the appropriate units.
Enter your answer in the provided box.Calculate the heat (in kJ) associated with the cooling of 348 g of mercury from 55.6 °C to 12.0 °C.
A 38.40 g sample of a substance is initially at 21.6 °C. After absorbing 2597 J of heat, the temperature of the substance is 126.6 °C. What is the specific heat (c) of the substance?
When 2112 J of heat energy is added to 45.8 g of ethanol. C2H6O, the temperature increase by 18.8°C. Calculate the molar heat capacity of C2H6O.
Titanium reacts with iodine to form titanium(III) iodide, emitting heat. 2Ti (s) + 3I2 (g) → 2TiI3 (s)           ΔH°rxn = 839 kJ Part ADetermine the masses of titanium and iodine that react if 1.69 x 103 kJ of heat is emitted by the reaction. Express your answer using three significant figures. Part BExpress your answer using three significant figures.
What is the sign and magnitude of q when 21.6 g of liquid water at 27 °C cools and freezes to form ice at -13 °C? The freezing point of water is 0°C and Cw H2O(l) = 75.4 J/mol°C.  Express your answer with the appropriate units.
The specific heat of a certain type of cooking oil is 1.75 J/(g • °C). How much heat energy is needed to raise the temperature of 2.91 kg of this oil from 23°C to 191°C?
A 27.72 g sample of a substance is initially at 21.1°C. After absorbing 2781 J of heat, the temperature of the substance is 161.3°C. What is the specific heat (SH) of the substance? 
The specific heat of a certain type of metal is 0.128 J/(g • °C). What is the final temperature if 305 J of heat is added to 57.9 g of this metal initially at 20.0  °C?
Calculate the enthalpy of methanol (CH3OH(l) (MW = 32.0 g/mol), if a 2.885 g sample of methanol is burned in a bomb calorimeter (Kc = 727.1 J/°C) containing 1.200 kg of water (Cp = 4.184 J/°C). The temperature of the calorimeter increases by 11.38°C. a. 635 kJ/molb. -1.02 x 106 kJ/mol c. -726 kJ/mol  d. -91.9 kJ/mol  e. -65.4 kJ/mol 
Part CTypically, water runs through the baseboard copper tubing and, therefore, fresh hot water is constantly running through the piping. However, consider a pipe where was allowed to sit in the pipe. The hot water cools as it sits in the pipe. What is the temperature change. (ΔT), of the water if 202.0 g of water sat in the copper pipe from part A, releasing 1760. J of the pipe. The specific heat of water is 4.184 J/(g •°C). Express your answer to four significant figures.
An 80 0-gram sample of a gas was heated from 25°C to 225°C. During this process. 346 J of work was done by vie system and its internal energy increased by 9225 J. What is the specific heat of the gas?
Be sure to answer all parts.A 0.1775-g sample of solid magnesium is burned in a constant-volume bomb calorimeter that has a heat capacity of 3024 J/°C. The temperature Increases by 1.452°C. (a) Calculate the heat given off by the burning Mg in kJ/g. (b) Calculate the heat given off by the burning Mg in kJ/mol. 
Enter your answer in the provided box.A sheet of gold weighing 8.2 g and at a temperature of 17.6 °C is placed flat on a sheet of iron weighing 18.1 g and at a temperature of 52.6 °C. What is the final temperature of the combined metals? Assume that no heat is lost to the surroundings. 
Calculate the amount of heat required to heat a 50 kg sample of ethanol from 13.0°C to 17.0°C. Specific heat capacity of ethanol is 2.42 J/g°C.
Enter your answer in the provided box.A 25.95-g sample of methanol at 35.6 °C is added to a 38.65-g sample of ethanol at 24.7 °C in a constant-pressure calorimeter. If the final temperature of the combined liquids is 28.5 °C and the heat capacity of the calorimeter is 19.3 J/°C, determine the specific heat of methanol. J/g • C
At 1 atm, how much energy is required to heat 79.0 g of H 2O(s) at -18.0°C to H 2O(g) at 163.0°C? Helpful constants can be found here.
Suppose you had a bomb calorimeter containing 500 mL of water at 25°C that you wanted to heat to exactly 95°C. You are using as a fuel the saturated fatty acid hexanedecanioc acid (C16H32O2), more commonly known as palmitic acid found in palm oil and animal fats. Use the following information to calculate how many grams of palmitic acid you should place into the bomb.Cbomb = 900 J/°C Cwater = 4.184 J/g°C density of water = 1.0 g/mL ΔHC-16.0 = 10, 071 kJ/mol (Heat of combustion of palmitic acid, assume ΔH = ΔE)
When 48.0 J of heat are added to 13.2 g of a liquid, its temperature rises by 1.78°C. What is the heat capacity of the liquid?
If you combine 370.0 mL of water at 25.00 ° C and 110.0 mL of water at 95.00 °C. what is the final temperature of the mixture? Use 1.00 g/mL as the density of water.
A 35 gram sample of copper (Csp(Cu) = 0 685 J/(g°C) is placed in a constant-pressure calorimeter containing 100 g of water that just stopped boiling. After some time the temperature of the water becomes constant at 92.3°C. What was the initial temperature of the copper block? Assume no heat is lost to the surroundings.
During an experiment, a student adds 1.23 g of CaO to 200.0 mL of 0.500 M HCI. The student observes a temperature increase of 5.10°C. Assuming the solution's final volume is 200.0 mL, the density if 1.00 g/mL, and the heat capacity is 4.184 J/(g.°C), calculate the heat of the reaction, ΔHrxn.CaO (s) + 2H+ (aq) → Ca2+ (aq) + H2O (l) 
An 80.0-gram sample of a gas was heated from 25°C to 225°C. During this process, 346 J of work was done by the system and its internal energy increased by 7435 J. What is the specific heat of the gas? 
A silver block, initially at 56.1°C is submerged into 1000 g of water at 24.2°C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 26.3°C.Part A What is the mass of the silver block? Express your answer to two significant figures and include the appropriate units. 
Heat is applied to change the temperature of a water sample from 11.5°C to 25.0°C. If the sample welighs 86.45g, how much heat is needed? (a) 4.55 kJ (b) 4.88 kJ (c) 4.25 kJ(d) 4.74 kJ 
How much heat is needed to raise the temperature of 107.0 g of water from 36°C to 96°C?
When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 3.50 g of CuSO4 (s) are dissolved in 115.90 g of water, the temperature of the solution increases from 24.19 to 27.48°C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.78 J/°C. Based on the student's observation, calculate the enthalpy of dissolution of CuSO4 (s) in kJ/mol. Assume the specific heat of the solution is equal to the specific heat of water. 
Exactly 10.1 mL of water at 31.0°C are added to a hot iron skillet. All of the water is converted into steam at 100.0°C. The mass of the pan is 1.50 kg and the molar heat capacity of iron is 25.19 J/(mol • °C). What is the temperature change of the skillet?
If 285 grams of water at 21 °C absorbs 287 kJ of heat from a mountain climber's stove at an elevation where the boiling point of water is 87 °C, is this amount of energy sufficient to heat the water to its boiling point?           (a) Yes           (b) No How many kJ are required to heat the water to its boiling point?
The temperature of a sample of iron increased by 27°C when 261 J of heat was applied. What is the mass of the sample? 
What is the specific heat of copper if it takes 93.8 cal to raise the temperature of a 85 g copper bar by 12.0. Express your answer using two significant figures.
The heat of vaporization of water is 40.66 kJ/mol. How much heat is absorbed when 2.04 g of water boils at atmospheric pressure? 
Calculate the amount of heat required to raise the temperature of a 38 g sample of water from 9°C to 22°C. 
Suppose that 1.14 g of rubbing alcohol (C6H8O) evaporates from a 70.0 g aluminum block. Part AIf the aluminum block is initially at 25°C, what is the final temperature of the block after the evaporation of the alcohol? Assume that the heat required for the vaporization of the alcohol comes only from the aluminum block and that the alcohol vaporizes at 25°C. Heat of vaporization of the alcohol at 25°C in 45.4 kJ/,mol. Express your answer using two significant figures.
A 26.6 g sample of Au metal (c = 0.13 J/g°C) is heated to 88.0°C and then placed into a beaker containing 173 g of 13.4 °C water (c = 4.184 J/g°C). The metal and water are then left until they come to equilibrium. What is ΔT for Au given to three significant figures?
Part ASome homes that use baseboard heating use copper tubing. Hot water runs through and heats the copper tubing, which in turn heats aluminum fins is actually the aluminum fins that heat air rising through the fins. How much energy would it take to heat a section of the copper tubing that weighs about 505.0 g, from 13.33°C to 22.38°C ? Copper has a specific heat of 0 3850 J/g • °C). Express your answer to four significant figures. 
If 1495 J of heat is needed to raise the temperature of a 318 g sample of a metal from 55.0°C to 66.0°C, what is the specific heat capacity of the metal?
In the laboratory a "coffee cup " calorimeter, or constant pressure calorimeter, is frequently used to determine the specific heat of a solid, or to measure the energy of a solution phase reaction. A student heats 69.07 grams of iron to 97.56°C and then drops it into a cup containing 81.71 grams of water at 22.09°C. She measures the final temperature to be 28.09°C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.82 J/°C. Assuming that no heat is lost to the surroundings calculate the specific heat of iron. 
Zinc metal reacts with hydrochloric acid according to the following balanced equation. Zn (s) + 2HCl (aq) → ZnCl2 (aq) + H2 (g) When 0.116 g of Zn(s) is combined with enough HCl to make 52.3 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 21.5 °C to 24.7 °C. Part AFind ΔHrxn for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g • °C as the specific heat capacity.)
A researcher studying the nutritional value of a new candy places a 4.60-gram sample the candy inside a bomb calorimeter and combusts it in excess oxygen. The observed temperature increase is 2.81°C. If the heat capacity of the calorimeter is 38.20 kJ • K-1, how many nutritional Calories are there per gram of the candy?
A pure sample of pure (E)-2, 5-dimethyl-3-hexene (C 8H16) is combusted in a bomb calorimeter. If the combustion of 0.871 g of (E)-2, 5-dimethyl-3-hexene results in a rise in temperature from 25.66°C to 32.77°C, what is the heat capacity (in kJ/K) of the calorimeter? Report your answer to three significant figures. The heat of combustion for (E)-2, 5-dimethyl-3-hexene is -5275.50 kJ/mol.
The specific heat of solid copper is 0.385 J/(g • °C). What thermal energy change occurs when the temperature of a 53.60 g sample of copper is cooled from 44.3 °C to 10.2 °C? Be sure to give your answer the proper sign. This amount of heat is used to melt solid ice at 0.0 °C. The molar heat of fusion of ice is 6.00 kJ/mol. How many moles of ice are melted?
When a 8.00-g sample of RbBr is dissolved in water in a calorimeter that has a total heat capacity of 4.816 kJ • K-1, the temperature decreases by 0.220 K. Calculate the molar heat of solution of RbBr.
You may want to reference ( pages 349-355) section 10.4 while comparing this problem.An unknown mass of each of the following substances, initially at 23°C, absorbs 1980 J of heat. The final temperature is recorded as indicated. Find the mass of each substance.Part Cethanol (Tf = 44.4°C) Express your answer using two significant figures. water (Tf = 32.2°C) Express your answer using two significant figures.
Part AIf you used the 8400 kilojoules you expend in energy in one day to heat 60000 g of water at 10°C, what would be the rise in temperature? Express your answer using one significant figure. Part BWhat would be the new temperature of the water? Express your answer using one significant figure. 
A hot tub is filled with 450 gal of water. (Figure 1) Part B What is the mass, in kilograms, of water in the tub? Express your answer to two significant figures and include the appropriate units. Part C How many kilocalories are needed to heat the water from 34°F to 177°F? Express your answer to two significant figures. 
If you combine 350.0 mL of water at 25.00°C and 110.0 mL of water at 95.00°C, what is the final temperature of the mixture? Use 1.00 g/mL as the density of water.
The heat capacity of an object indicates how much energy that object can absorb for a given increase in that objects temperature. In a system in which two objects of different temperatures come into contact with one another, the warmer object will cool and the cooler object will warm up until the system is at a single equilibrium temperature. Note the difference between the terms molar heat capacity, which has units of J/(mol • °C), and specific heat, which has units of J/(g • °C). A volume of 110. mL of H2O is initially at room temperature (22.00 °C). A chilled steel rod at 2.00 °C is placed in the water. If the final temperature of the system is 21.40 °C, what is the mass of the steel bar? Use the following values: specific heat of water = 4.18 J/(g • °C) specific heat of steel = 0.452 J/(g • °C) Express your answer to three significant figures and include the appropriate units.
An insulated container is used to hold 43.40 g of water at 35.80 °C. A sample of copper weighing 14.10 g is placed in a dry test tube and heated for 30 minutes in a boiling water bath at 100.10 °C. The heated test tube is carefully removed from the water bath with laboratory tongs and inclined so that the copper slides into the water in the insulated container. Given that the specific heat of solid copper is 0.385 J/(g • °C), calculate the maximum temperature of the water in the insulated container after the copper metal is added.
When a 6.50-g sample of solid sodium hydroxide dissolves in 100.0 g of water in a coffee-cup calorimeter (the following Figure), the temperature rises from 21.6 degree C to 37.8°C. Calculate ΔH (in kJ/mol NaOH) for the solution process NaOH(s) → Na+ (aq) + OH- (aq) Assume that the specific heat of the solution is the same as that of pure water.Express your answer with the appropriate units.
Why is it reasonable to assume the specific heats of NaOH and HCl solutions are the same as water, 4.18 J/g•°C?
661 cal of heat is added to 5.00 g ice at -20.0 °C. What is the final temperature of the water? 
The specific heat of aluminum is 0.900 J/g • °C. How many joules of heat are absorbed by 15.0 g of Al if it is heated from 20.0°C to 60.0°C x 104a. 270 Jb. 2.40 Jc. 540 Jd. 812 Je. 0.000117 J 
The specific heat of water is 4.18 J/(g⋅∘C). Calculate the molar heat capacity of water.