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Thermochemical Equations Solutions Library

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142 solutions

Thermochemical Equations

Q. How much energy is evolved during the formation of 98.7 g of Fe, according to the reaction below? Fe2O3(s) + 2 Al(s) → Al2O3(s) + 2 Fe(s)  ΔH°rxn =...

Solved • Nov 4, 2020

Thermochemical Equations

Q. Part C. Calculate the enthalpy change for the thermite reaction:2Al(s) + Fe2O3(s) → 2Fe(s) + Al2O3(s) ΔH°rxn = − 850 kJwhen 6.00 mol of Al undergoe...

Solved • Jul 2, 2020

Thermochemical Equations

Q. The decomposition of NI3 to form N2 and I2 releases − 290.0 kJ of energy. The reaction can be represented as2NI3(s) → N2(g) + 3I2(g), ΔHrxn = − 290...

Solved • Jul 2, 2020

Thermochemical Equations

Q. For the reaction given in Part A, how much heat is absorbed when 3.60 mol of A reacts?Express your answer to three significant figures and include ...

Solved • Jul 2, 2020

Thermochemical Equations

Q. How many liters of C6H14(l), measured at 20° C, must be burned to provide enough heat to warm 26.8 m3 of water from 18.3 to 33.2°C , assuming that ...

Solved • Jul 2, 2020

Thermochemical Equations

Q. Part C. Methane, when liquefied, has a density of 0.466 g/ mL, the density of methanol is 0.791 g/ mL at 25°C. Calculate the enthalpy of combustion...

Solved • Jul 2, 2020

Thermochemical Equations

Q. World energy supplies are often measured in the unit of quadrillion British thermal units (1012 Btu), generally called a "quad." In 2015, world ene...

Solved • Jun 30, 2020

Thermochemical Equations

Q. World energy supplies are often measured in the unit of quadrillion British thermal units (1012 Btu), generally called a "quad." In 2015, world ene...

Solved • Jun 30, 2020

Thermochemical Equations

Q. The complete combustion of ethanol, C2H5OH (FW = 46.0 g/mol), proceeds as follows: C2H5OH(l) + 3 O2 (g) → 2 CO2 (g) + 3 H2O(l) ΔH = − 555 kJ What i...

Solved • Jun 30, 2020

Thermochemical Equations

Q. Consider the following thermochemical equation:2A → AA       ΔHrxn = -42.5 JWhat is the heat associated with the reaction of 8 moles of AExpress yo...

Solved • Jun 25, 2020

Thermochemical Equations

Q.  Hydrogen and methanol have both been proposed as alternatives to hydrocarbon fuels.How does the energy of these fuels compare to that of octane (C...

Solved • Jun 25, 2020

Thermochemical Equations

Q.  Hydrogen and methanol have both been proposed as alternatives to hydrocarbon fuels.Which fuel contains the most energy in the least mass?

Solved • Jun 25, 2020

Thermochemical Equations

Q. The enthalpy for the formation of 1 mole of NH3(aq) is -80.29 kJ/mol. What is the ΔHf for the formation of 3 moles of NH3(aq)?

Solved • May 1, 2020

Thermochemical Equations

Q. The oxidation of copper(I) oxide, Cu2O(s), to copper(II) oxide, CuO(s), is an exothermic process, 2 Cu2O(s) + O2(g) → 4 CuO (s). The change in enth...

Solved • Apr 29, 2020

Thermochemical Equations

Q. Consider the following reaction: 2Mg(s) + O2(g) → 2MgO(s)        ΔH = -1204 kJHow many grams of MgO are produced during an enthalpy change of -238 ...

Solved • Apr 21, 2020

Thermochemical Equations

Q. Consider the following reaction: 2 Mg(s) + O2(g) → 2MgO(s)        ΔH = -1204 kJIs this reaction exothermic or endothermic? Calculate the amount of ...

Solved • Apr 21, 2020

Thermochemical Equations

Q. For the following reaction, what is ∆H° when 25.0 g of Na2O2(molar mass = 77.98 g mol−1) is reacted with water?2 Na2O2(s) + 2 H2O(l) → 4 NaOH(s) + ...

Solved • Nov 29, 2019

Thermochemical Equations

Q. For the reactionH2(g) + 1/2O2(g) --> H2O(l)              deltaH = –286 kJ/molcalculate the enthalpy change when 2.66 g of water is produced.1. 7...

Solved • Nov 21, 2019

Thermochemical Equations

Q. How much energy (kJ) is required to vaporize 158 g of butane (C4H10) at its boiling point, if Δvap is 24.3 kJ/mole?(a) 15.1 kJ(b) 66.1 kJ(c) 89.4 k...

Solved • Nov 1, 2019

Thermochemical Equations

Q. How much energy is evolved during the reaction of 51.2 g of Al, according to the reaction below?Assume that there is excess Fe2O3.Fe2O3(s) + 2 Al(s...

Solved • Oct 25, 2019

Thermochemical Equations

Q. Given the thermochemical equation: 4 Fe(s) + 3 O2(g) ⟶ 2 Fe2O3(s)         ΔHrxn = –1652 kJ mol–1 What is the ΔH for the reaction when 500.0 g of Fe...

Solved • Oct 4, 2019

Thermochemical Equations

Q. The value of ΔH° for the reaction below is +128.1 kJ:CH3OH(l) → CO(g) + 2H2(g)How many kJ of heat are consumed when 5.10 g of CO(g) is formed as sh...

Solved • Sep 24, 2019

Thermochemical Equations

Q. The value of ΔH° for the reaction below is -790 kJ. The enthalpy change accompanying the reaction of 0.95 g of S is __________ kJ.                 ...

Solved • Sep 13, 2019

Thermochemical Equations

Q. For the reaction, CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l), ΔH = -890 kJ, what will be the change in enthalpy when 3 moles of methane reacts in exces...

Solved • Aug 27, 2019

Thermochemical Equations

Q. In a constant-pressure calorimeter, 70.0 mL of 0.320 M Ba(OH) 2 was added to 70.0 mL of 0.640 M HCl. The reaction caused the temperature of the sol...

Solved • Aug 7, 2019

Thermochemical Equations

Q. A propane tank on a home barbeque contains 11.3x103 g of propane. Use the value for ΔHrxn (-2044 kJ/mol) to calculate the total amount of heat prod...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Butane combusts according to the equation: C4H10(g) + 13/2 O2(g) → 4 CO2(g) + 5 H2O(g); ΔH˚rxn = -2658 kJ. What mass of butane in grams is necessar...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Butane combusts according to the equation: C4H10(g) + 13/2 O2(g) → 4 CO2(g) + 5 H2O(g); ΔH˚rxn = -2658 kJ. What mass of CO2 is produced in the evol...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Ammonia reacts with oxygen according to the equation: 4 NH3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(g); ΔHrxn = -906 kJ. Calculate the heat (in kJ) associat...

Solved • Nov 12, 2018

Thermochemical Equations

Q. You may want to reference (Pages 271 - 272) Section 6.7 while completing this problem.The addition of hydrochloric acid to a silver nitrate solutio...

Solved • Nov 12, 2018

Thermochemical Equations

Q. What mass of natural gas (CH4) must you burn to emit 268 kJ of heat?CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g)             Hrxno= –802.3 kJ/mol

Solved • Nov 12, 2018

Thermochemical Equations

Q. Charcoal is primarily carbon. What mass of CO2 is produced if you burn enough carbon (in the form of charcoal) to produce 5.10 x 102 kJ of heat? Th...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Determine the mass of CO2 produced by burning enough of methane to produce 2.25x102 kJ of heat.CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g); ΔH˚rxn= -802.3 kJ

Solved • Nov 12, 2018

Thermochemical Equations

Q. Determine the mass of CO2 produced by burning enough of propane to produce 2.25x102 of heat.C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g); H˚rxn= - 2217 kJ

Solved • Nov 12, 2018

Thermochemical Equations

Q. Determine the mass of CO2 produced by burning enough of octane to produce 2.25x102 of heat.C8H18(l) + 25/2 O2(g) → 8 CO2(g) + 9 H2O(g); ΔH˚rxn= - 5...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Hydrogen gas reacts with oxygen to form water.2 H2(g) + O2(g) → 2 H2O(g)         ΔH = –483.5 kJ/molDetermine the minimum mass of hydrogen gas requi...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Natural gas burns in air to form carbon dioxide and water, releasing heat.CH4(g) + O2(g) → CO2(g) + H2O(g); ΔHrxn˚ = –802.3 kJ/molWhat minimum mass...

Solved • Nov 12, 2018

Thermochemical Equations

Q. The propane fuel (C3H8) used in gas barbecues burns according to the following thermochemical equation: C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g); ΔH...

Solved • Nov 12, 2018

Thermochemical Equations

Q. A large sport utility vehicle has a mass of 2600 kg. Calculate the mass of CO2 emitted into the atmosphere upon accelerating the SUV from 0.0 mph t...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Combustion of natural gas (primarily methane) occurs in most household heaters. The heat given off in this reaction is used to raise the temperatur...

Solved • Nov 12, 2018

Thermochemical Equations

Q. A gaseous fuel mixture contains 23.1% methane (CH4), 41.1% ethane (C2H6) and the rest propane (C3H8) by volume.When the fuel mixture contained in a...

Solved • Nov 12, 2018

Thermochemical Equations

Q. LP gas burns according to the following exothermic reaction: C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g); ΔH˚rxn= -2044 kJ. What mass of LP gas is nece...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Consider the following thermochemical equation for the combustion of acetone (C3H6O), the main ingredient in nail polish remover: C3H6O(l) + 4 O2(g...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Nitromethane (CH3NO2) burns in air to produce significant amounts of heat: 2 CH3NO2(l) + 3/2 O2(g) → 2 CO2(g) + 3 H2O(l) + N2(g); ΔH˚rxn = -1418 kJ...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Titanium reacts with iodine to form titanium(III) iodide, emitting heat, via the following reaction: 2 Ti(s) + 3 I2(g) → 2 TiI3(s); ΔH˚rxn= -839 kJ...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Titanium reacts with iodine to form titanium(III) iodide, emitting heat, via the following reaction: 2 Ti(s) + 3 I2(g) → 2 TiI3(s); ΔH˚rxn= -839 kJ...

Solved • Nov 12, 2018

Thermochemical Equations

Q. Natural gas is very abundant in many Middle Eastern oil fields. However, the costs of shipping the gas to markets in other parts of the world are h...

Solved • Oct 31, 2018

Thermochemical Equations

Q. C6H12O6(s) + 6 O2(g) → 6 CO2(g) + 6 H2O(l), Δ;;;;;;H = –2803 kJBased on the enthalpy of the above reaction, what is the fuel value of glucose on a ...

Solved • Oct 31, 2018

Thermochemical Equations

Q. A pound of plain M&M candies contains 96 g fat, 320 g carbohydrate, and 21 g protein.Table 5.5: Compositions and Fuel ValuesFuelValuekcal/g(Cal...

Solved • Oct 31, 2018

Thermochemical Equations

Q. The automobile fuel called E85 consists of 85% ethanol and 15% gasoline. E85 can be used in so-called flex-fuel vehicles (FFVs), which can use gaso...

Solved • Oct 31, 2018

Thermochemical Equations

Q. The automobile fuel called E85 consists of 85% ethanol and 15% gasoline. E85 can be used in so-called flex-fuel vehicles (FFVs), which can use gaso...

Solved • Oct 31, 2018

Thermochemical Equations

Q. At the end of 2012, global population was about 7.0 billion people. What mass of glucose in kg would be needed to provide 1600 cal/ person / day of...

Solved • Oct 31, 2018

Thermochemical Equations

Q. Meals-ready-to-eat (MREs) are military meals that can be heated on a flameless heater. The heat is produced by the following reaction: Mg(s) + 2 H2...

Solved • Oct 31, 2018

Thermochemical Equations

Q. Ozone, O3(g), is a form of elemental oxygen that is important in the absorption of ultraviolet radiation in the stratosphere. It decomposes to O2(g...

Solved • Oct 31, 2018

Thermochemical Equations

Q. You may want to reference (Pages 172 - 176)Section 5.3 while completing this problem.Consider the following reaction: 2 CH3OH(g) → 2 CH4(g) + O2(g)...

Solved • Oct 31, 2018

Thermochemical Equations

Q. You may want to reference (Pages 172 - 176)Section 5.3 while completing this problem.Consider the following reaction: 2 CH3OH(g) → 2 CH4(g) + O2(g)...

Solved • Oct 31, 2018

Thermochemical Equations

Q. You may want to reference (Pages 172 - 176)Section 5.3 while completing this problem.Consider the following reaction: 2 CH3OH(g)  →  2CH4(g) + O2 (...

Solved • Oct 31, 2018

Thermochemical Equations

Q. Consider the following reaction: 2 Mg(s) + O2(g) → 2 MgO(s), ΔH = –1204 kJCalculate the amount of heat transferred when 3.56 g of Mg(s) reacts at c...

Solved • Oct 31, 2018

Thermochemical Equations

Q. Consider the following reaction: 2 Mg(s) + O2(g) → 2 MgO(s), ΔH = –1204 kJHow many grams of MgO are produced during an enthalpy change of –234 kJ ?

Solved • Oct 31, 2018

Thermochemical Equations

Q. Consider the following reaction:2Mg(s) + O2 (g) → 2MgO(s) ΔH = - 1204How many kilojoules of heat are absorbed when 40.5 g of MgO(s) is decomposed i...

Solved • Oct 31, 2018

Thermochemical Equations

Q. When solutions containing silver ions and chloride ions are mixed, silver chloride precipitates: Ag+(aq) + Cl–(aq) → AgCl(s), ΔH = –65.5 kJCalculat...

Solved • Oct 31, 2018

Thermochemical Equations

Q. When solutions containing silver ions and chloride ions are mixed, silver chloride precipitates: Ag+(aq) + Cl–(aq) → AgCl(s), ΔH = –65.5 kJCalculat...

Solved • Oct 31, 2018

Thermochemical Equations

Q. When solutions containing silver ions and chloride ions are mixed, silver chloride precipitates: Ag+(aq) + Cl–(aq) → AgCl(s), ΔH = –65.5 kJCalculat...

Solved • Oct 31, 2018

Thermochemical Equations

Q. At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g), ΔH = –8...

Solved • Oct 31, 2018

Thermochemical Equations

Q. At one time, a common means of forming small quantities of oxygen gas in the laboratory was to heat KClO3: 2 KClO3(s) → 2 KCl(s) + 3 O2(g), ΔH = –8...

Solved • Oct 31, 2018

Thermochemical Equations

Q. It is estimated that the net amount of carbon dioxide fixed by photosynthesis on the landmass of the Earth is 5.5 x 1016 g of CO2. All this carbon ...

Solved • Oct 31, 2018

Thermochemical Equations

Q. Consider the decomposition of liquid benzene, C6H6(l), to gaseous acetylene, C2H2(g): C6H6(l) → 3 C2H2(g), ΔH = +630 kJWhat is ΔH for the formation...

Solved • Oct 31, 2018

Thermochemical Equations

Q. The overall reaction in a commercial heat pack can be represented as:4Fe (s)+ 3 O2 (g) → 2Fe2O3              ΔH = -1652 kJa. How much heat is relea...

Solved • Oct 17, 2018

Thermochemical Equations

Q. How much heat is produced by combustion of 125 g of methanol under standard state conditions?

Solved • Oct 16, 2018

Thermochemical Equations

Q. Compounds of boron and hydrogen are remarkable for their unusual bonding and also for their reactivity. With the more reactive halogens, for exampl...

Solved • Oct 15, 2018

Thermochemical Equations

Q. When 1 mol of NO(g) forms from its elements, 90.29 kJ of heat is absorbed. What is ΔH when 3.50 g of NO decomposes to its elements?

Solved • Oct 15, 2018

Thermochemical Equations

Q. Consider the following balanced thermochemical equation for a reaction sometimes used for H2S production:1/8S8 (s) + H2 (g) ⟶ H2S (g)              ...

Solved • Oct 15, 2018

Thermochemical Equations

Q. A chemist measures the energy change ΔH during the following reaction: CH4 (g)+2O2 (g) → CO2 (g) + 2H2O (l)     ΔH = -882. kJUse the information to...

Solved • Oct 5, 2018

Thermochemical Equations

Q. The total volume of hydrogen gas needed to fill the Hinderburg was 2.00 x 108 L at 1.00 atm and 25.0°C. How much energy was evolved when it burned?...

Solved • Oct 1, 2018

Thermochemical Equations

Q. Titanium reacts with iodine to form titanium(III) iodide, emitting heat. 2Ti (s) + 3I2 (g) → 2TiI3 (s)           ΔH°rxn = 839 kJ Part ADetermine th...

Solved • Sep 7, 2018

Thermochemical Equations

Q. 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 ...

Solved • Sep 3, 2018

Thermochemical Equations

Q. If the heat of combustion for a specific compound is -1110.0 kJ/mol and its molar mass is 36.79 g/mol, how many grams of this compound must you bur...

Solved • Aug 8, 2018

Thermochemical Equations

Q. 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...

Solved • Aug 8, 2018

Thermochemical Equations

Q. The following thermochemical equation is for the reaction of bromine trifluoride(g) to form bromine(g) and fluorine(g). 2BrF3 (g) → Br2 (g) + 3F2 (...

Solved • Jul 18, 2018

Thermochemical Equations

Q. The reaction of cyanamide, NH2CN(s), with oxygen was run in a bomb calorimeter, and ΔE was found to be -742.7 kJ/mol of NH2CN(s) at 298 K. Calculat...

Solved • Jul 17, 2018

Thermochemical Equations

Q. How much heat energy is required to boil 30.5 g of ammonia, NH3? The molar heat of vaporization of ammonia is 23.4 kJ/mol. 

Solved • Jul 16, 2018

Thermochemical Equations

Q. Enter your answer in the provided box.Liquid methanol (CH3OH) can be used as an alternative fuel in pickup and SUV engines. An industrial method fo...

Solved • Jul 9, 2018

Thermochemical Equations

Q. Be sure to answer all parts.Stearic acid (C18H36O2) is a typical fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (CO...

Solved • Jul 9, 2018

Thermochemical Equations

Q. When a 5.00-g sample of KCI is dissolved in water in a calorimeter that has a total heat capacity of 2.683 kJ • K-1, the temperature decreases by 0...

Solved • Jul 4, 2018

Thermochemical Equations

Q. When a 2.050 gram sample of methanol (CH3OH) was burned in air, it released 40.81 kilojoules (kJ) of heat. Calculate the enthalpy change for the co...

Solved • Jun 19, 2018

Thermochemical Equations

Q. The oxidation of copper (l) oxide, Cu 2O(s), to copper(II) oxide, CuO(s), is an exothermic process, 2Cu2O(s) + O2(g) → 4CuO(s)                    Δ...

Solved • Jun 6, 2018

Thermochemical Equations

Q. When solutions containing silver ions and chloride ions are mixed, silver chloride precipitates: Ag+ (ag) + Cl - (aq) → AgCI(s)       Δ H = - 65.5 ...

Solved • May 30, 2018

Thermochemical Equations

Q. At the end of 2012, global population was about 7.0 billion people. What mass of glucose in kg would be needed to provide 1600 cal/person/day of no...

Solved • May 29, 2018

Thermochemical Equations

Q. If the heat of combustion for a specific compound is -1090.0 kJ/mol and its molar mass is 48.47 g/mol, how many grams of this compound must you bur...

Solved • May 21, 2018

Thermochemical Equations

Q. How much heat in kilojoules is evolved or absorbed in each of the following reactions?Burning of 15.5 g of propane:C3H8(g) + 5 O2(g) → 3 CO2(g) + C...

Solved • May 21, 2018

Thermochemical Equations

Q. 661 cal of heat is added to 5.00 g ice at -20.0 °C. What is the final temperature of the water? 

Solved • May 20, 2018

Thermochemical Equations

Q. A gas mixture at 580.0°C and 113 kPa absolute enters a heat exchanger at a rate of 80.0 m3/hr. The gas leaves the heat exchanger at 150.0°C. The ch...

Solved • May 12, 2018

Thermochemical Equations

Q. Consider the following thermochemical equation for the combustion of acetone (C3H4O), the main ingredient in nail polish remover. C3H6O(l) + 4 O2(g...

Solved • May 4, 2018

Thermochemical Equations

Q. The combustion of hexane is given by the following reaction. 2C6H14 + 19O2 --> 12CO2 + 14H2O The enthalpy of reaction is -4163.0 kJ/mol. How muc...

Solved • May 4, 2018

Thermochemical Equations

Q. Hydrazine, N2H4, is a liquid used as a rocket fuel. It reacts with oxygen to yield nitrogen gas and water.N2H4 (l) + O2 (g) → N2 (g) + 2 H2O (l)The...

Solved • May 4, 2018

Thermochemical Equations

Q. The reaction for the combustion of propane is shown below. C3H8(g) + 5 O2 (g) → 3 CO2 (g)  + 4 H2O (l)    ΔH = - 526.3 kcal/molHow much heat is  re...

Solved • Apr 3, 2018

Thermochemical Equations

Q. What is the minimum energy required to decompose 765 g of PCl 3, according to the reaction below? The molar mass of PCl3 is 137.32 g/mol. 4PCl3(g) ...

Solved • Apr 2, 2018

Thermochemical Equations

Q. The enthalpy of neutralization for the reaction of HNO3 with KOH is given below.HNO3 (aq) + KOH (aq) → H2O (l) + KNO3 (aq)    ΔH = -57.0 kJ102.4 ml...

Solved • Mar 21, 2018

Thermochemical Equations

Q. Calcium oxide and water react in an exothermic reaction:CaO(s) + H2O(l) → Ca(OH)2(s)       Heat of reaction (Rxn) = -64.8 kJ/molHow much heat would...

Solved • Mar 21, 2018

Thermochemical Equations

Q. What volume of benzene (C6H6, d= 0.88 g/mL, molar mass = 78.11 g/mol) is required to produce 1.5 x 103 kJ of heat according to the following reacti...

Solved • Mar 20, 2018