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Endothermic & Exothermic Reactions Solutions Library

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Endothermic & Exothermic Reactions

Q. Based on their descriptions, classify these chemical changes as endothermic or exothermic.-A chemical change takes place in a container, making it ...

Solved • Mar 20, 2020

Endothermic & Exothermic Reactions

Q. Consider this reactionC2H5OH + 3 O2 → 2 CO2 + 3 H2O    ΔH = -1370 kJ/molWhat is the enthalpy for this reaction reversed?reaction reversed: 2CO2 + 3...

Solved • Mar 17, 2020

Endothermic & Exothermic Reactions

Q. Determine the enthalpy of solution for a solid with ΔH values as described in each scenario. Drag the appropriate items to their respective bins.

Solved • Mar 12, 2020

Endothermic & Exothermic Reactions

Q. Which of the following is true if an exothermic reaction occurs out in a coffee-cup calorimeter?A. ΔH of the reactants is lower than ΔH of the prod...

Solved • Oct 9, 2019

Endothermic & Exothermic Reactions

Q. A chemical reaction absorbs heat from the surroundings. Therefore it is _________ and has a ________ value of ΔH.A. endothermic, negative B. endoth...

Solved • Oct 3, 2019

Endothermic & Exothermic Reactions

Q. Which one of the following is an endothermic process?A) ice meltingB) water freezingC) boiling soupD) Hydrochloric acid and barium hydroxide are mi...

Solved • Sep 24, 2019

Endothermic & Exothermic Reactions

Q. Which of these physical changes would require the liberation of energy, exothermic?a. melting pointb. boiling pointc. condensation of steam to form...

Solved • Aug 30, 2019

Endothermic & Exothermic Reactions

Q. Is deposition endothermic or exothermic?

Solved • Aug 25, 2019

Endothermic & Exothermic Reactions

Q. Why is melting ice an endothermic reaction?

Solved • Aug 7, 2019

Endothermic & Exothermic Reactions

Q. Based on their descriptions, classify these chemical changes as endothermic or exothermic.

Solved • Aug 2, 2019

Endothermic & Exothermic Reactions

Q. 5.81Without doing any calculations, predict the sign of ΔH for each of the following reactions:(b) 2H(g) → H2(g)

Solved • Jan 23, 2019

Endothermic & Exothermic Reactions

Q. What is the sign of ΔH for the process depicted in the figure above?

Solved • Jan 3, 2019

Endothermic & Exothermic Reactions

Q. Consider the vaporization of liquid water to steam at a pressure of 1 atm.Is this process endothermic or exothermic?

Solved • Jan 3, 2019

Endothermic & Exothermic Reactions

Q. When ammonium chloride (NH4Cl) is dissolved in water, the solution becomes colder. Is the dissolution of ammonium chloride endothermic or exothermic?

Solved • Dec 3, 2018

Endothermic & Exothermic Reactions

Q. Ethyl chloride (C2H5Cl) boils at 12 oC. When liquid C2H5Cl under pressure is sprayed on a room-temperature (25 oC) surface in air, the surface is c...

Solved • Nov 27, 2018

Endothermic & Exothermic Reactions

Q. Identify each process as endothermic or exothermic and indicate the sign of ΔH.(a) an ice cube melting(b) nail polish remover quickly evaporating a...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Indicate the sign of ΔH for the following processes.a. natural gas burning on a stoveb. isopropyl alcohol evaporating from skinc. water condensing ...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Determine whether each of the following is exothermic or endothermic.dry ice evaporating,a sparkler burning, andthe reaction that occurs in a chemi...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Indicate the sign of ΔH for the following processes.dry ice evaporating,a sparkler burning, andthe reaction that occurs in a chemical cold pack oft...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Determine whether each of the following is exothermic or endothermic.a. natural gas burning on a stoveb. isopropyl alcohol evaporating from skinc. ...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. From a molecular viewpoint, where does the energy emitted in an exothermic chemical reaction come from?

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. If an endothermic reaction absorbs heat, then why does it feel cold to the touch?

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Explain the difference between endothermic reactions and exothermic reactions with respect to the bond energies of the bonds broken and formed.

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Imagine a container placed in a tub of water, as depicted in the accompanying diagram.If the contents of the container are the system and heat is a...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. When a reaction occurs in a flask, you notice that the flask gets colder. What is the sign of ΔHDelta {H}?

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

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

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. For a given process at constant pressure, H is positive. Is the process endothermic or exothermic?

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. When a 4.25-g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter, the temperature drops from 22.0 oC to 16.9...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Calculate ΔE and determine whether the process is endothermic or exothermic for the following cases: (a) q = 0.763 kJ and w = -840 J. 

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. When H2(g) and O2(g) react to form H2O(l), heat is released to the surroundings. Consider the reverse reaction, namely, the formation of H2(g) and ...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Ethyl chloride (boiling point, 13 °C) is used as a local anesthetic. When the liquid is sprayed on the skin, it cools the skin enough to freeze and...

Solved • Oct 30, 2018

Endothermic & Exothermic Reactions

Q. Are the following processes exothermic or endothermic?a. the combustion of gasoline in a car engine

Solved • Oct 17, 2018

Endothermic & Exothermic Reactions

Q. Are the following processes exothermic or endothermic?d. F2 (g) → 2F (g)

Solved • Oct 17, 2018

Endothermic & Exothermic Reactions

Q. Are the following processes exothermic or endothermic?a. When solid KBr is dissolved in water, the solution gets colder.

Solved • Oct 17, 2018

Endothermic & Exothermic Reactions

Q. Are the following processes exothermic or endothermic?b. Natural gas (CH4) is burned in a furnace.

Solved • Oct 17, 2018

Endothermic & Exothermic Reactions

Q. Which produces more heat, Os(s) + 2O2(g) ⟶ OsO4(s) or Os(s) + 2O2(g) ⟶ OsO4(g)? For the phase change OsO4(s) ⟶ OsO4(g),    ΔH = 56.4 kJ

Solved • Oct 16, 2018

Endothermic & Exothermic Reactions

Q. Both graphite and diamond burn.C(s, diamond) + O2(g) ⟶ CO2(g)For the conversion of graphite to diamond:C(s, graphite) → C(s, diamond)              ...

Solved • Oct 16, 2018

Endothermic & Exothermic Reactions

Q. Draw an enthalpy diagram for a general endothermic reaction; label the axis, reactants, products, and ΔH with its sign.

Solved • Oct 15, 2018

Endothermic & Exothermic Reactions

Q. When 2 moles of C2H6 (g) react with O2 (g) to form CO2 (g) and H2O (g) according to the following equation, 2.86 x 103 kJ of energy are evolved. 2C...

Solved • Jul 18, 2018

Endothermic & Exothermic Reactions

Q. Which of the following reactions are exothermic?

Solved • Mar 30, 2018

Endothermic & Exothermic Reactions

Q. Predict whether the following reactions will be exothermic or endothermic.a. N2(g) + 3H2(g) → 2NH3(g)b. S(g) + O2(g) → SO2(g)c. 2H2O(g) → 2H2(g) + ...

Solved • Mar 27, 2018

Endothermic & Exothermic Reactions

Q. The formation of CsCl from Cs(s) and Cl 2(g) involves the following steps. Which of these steps absorb energy and which release energy?a. Cs(s) → C...

Solved • Mar 26, 2018

Endothermic & Exothermic Reactions

Q. The reaction between hydrogen and oxygen to form water is highly exothermic. Which statement is true of the energies of the bonds that break and fo...

Solved • Mar 26, 2018

Endothermic & Exothermic Reactions

Q. Which of the following is true of an endothermic reaction?a. Strong bonds break and weak bonds form: this means that more energy is released than a...

Solved • Mar 22, 2018

Endothermic & Exothermic Reactions

Q. Which process is endothermic?a. The burning of candle wax.b. The combustion of natural gas in a stove.c. The formation of a chemical bond.d. The me...

Solved • Mar 20, 2018

Endothermic & Exothermic Reactions

Q. Which statement is FALSE?a. ΔErxn is a measure of heat.b. Endothermic has a positive ΔH.c. An exothermic reaction gives heat off to the surrounding...

Solved • Mar 20, 2018

Endothermic & Exothermic Reactions

Q. Given w = 0, an endothermic reaction has which of the following:a. +ΔH and +ΔEb. -ΔH and -ΔEc. +ΔH and -ΔEd. -ΔH and +ΔE

Solved • Mar 20, 2018

Endothermic & Exothermic Reactions

Q. Which of the following processes is exothermic?a. a candle flameb. the vaporization of waterc. melting of iced. the chemical reaction in a "cold pa...

Solved • Mar 20, 2018

Endothermic & Exothermic Reactions

Q. Sort the following reactions as either endothermic or exothermic. Explain your answer briefly.

Solved • Mar 20, 2018

Endothermic & Exothermic Reactions

Q. Which of the following statements are true?a. ΔH for an endothermic reaction is positive.b. ΔH for an exothermic reaction is positive.c. When energ...

Solved • Mar 20, 2018

Endothermic & Exothermic Reactions

Q. Classify each process as endothermic or exothermic. What is the sign of ΔH for each process? a. Gasoline burning in an engineb. Steam condensing on...

Solved • Mar 19, 2018

Endothermic & Exothermic Reactions

Q. Sort the following reactions as either endothermic or exothermic.a. making popcorn in a microwave oven b. a burning match c. the reaction inside a ...

Solved • Mar 16, 2018

Endothermic & Exothermic Reactions

Q. Classify each process as an endothermic or exothermic process.1. forming solute-solvent attractions2. breaking solute-solute attractions3. breaking...

Solved • Mar 16, 2018

Endothermic & Exothermic Reactions

Q. Predict whether the following reactions will be exothermic or endothermic.a. N2(g)+3H2(g) → 2NH3b. S(g)+O2(g) → SO2(g)c. 2H2O(g) → 2H2(g) + O2(g)d....

Solved • Mar 16, 2018

Endothermic & Exothermic Reactions

Q. Predict whether the following reactions will be exothermic or endothermic. 

Solved • Mar 13, 2018

Endothermic & Exothermic Reactions

Q. Which one of the following processes is exothermic.a. H2(g) → 2H(g)b. 16CO2(g) +18H2O(l) → 2C8H18(l) + 25O2(g)c. H2(g) → H2O(l)d. CO2(s) → CO2(g)

Solved • Mar 13, 2018

Endothermic & Exothermic Reactions

Q. Classify the following phase changes as endothermic or exothermic.

Solved • Mar 8, 2018

Endothermic & Exothermic Reactions

Q. Which phase change, boiling or freezing of water, is exothermic? Explain.

Solved • Aug 18, 2017

Endothermic & Exothermic Reactions

Q. Which of the reactions below is an exothermic reaction? A) H2O (I) → H2O (s) B) H2O (I) → H2O (g) C) HCl (aq) + NaOH (aq) → NaCl (aq) + HO (I) (...

Solved • Aug 17, 2017

Endothermic & Exothermic Reactions

Q. A reaction under certain conditions has an enthalpy change of ΔH= -118kJ. This means that 118kJ of heat would be liberated:1. if the reaction were ...

Solved • Jul 5, 2017

Endothermic & Exothermic Reactions

Q. Identify each of the following processes as endothermic or exothermic and indicate the sign of ∆H.a) ice cube meltingb) water freezing in a freezer...

Solved • Jul 3, 2017

Endothermic & Exothermic Reactions

Q. A reaction under certain conditions has an enthalpy change of ∆H = −118 kJ. This means that 118 kJ of heat would be liberated 1. if the reaction w...

Solved • Jun 21, 2017

Endothermic & Exothermic Reactions

Q. Which of the following is an endothermic process?  (1) Chlorine gas expands while keeping a constant temperature. (∆E = 0) (2) Freezing gaseous c...

Solved • Jun 14, 2017

Endothermic & Exothermic Reactions

Q. Is the condensation of a gas an endothermic or exothermic process? ______________________

Solved • Dec 14, 2016

Endothermic & Exothermic Reactions

Q. Which of the following processes is exothermic?A) The formation of dew in the morning.B) The melting of ice.C) The chemical reaction in a "cold pac...

Solved • Oct 28, 2016

Endothermic & Exothermic Reactions

Q. How many of the following processes require energy (absorbs heat)? Phase transition from solid to gas Freezing Increasing the temperature of w...

Solved • Sep 13, 2016

Endothermic & Exothermic Reactions

Q. Consider the process of 2 H(g) → H2(g) where ΔH = −436 kJ/mol Determine if the sentence below is true or false. Reacting two moles of H(g) would ...

Solved • Aug 8, 2016

Endothermic & Exothermic Reactions

Q. Consider the process of 2 H(g) → H2(g) where ΔH = −436 kJ/molDetermine if the sentence below is true or false.The temperature of the surroundings w...

Solved • Aug 8, 2016

Endothermic & Exothermic Reactions

Q. In an exothermic chemical reaction: A + 2 B → C When the amount of A and B reacting is doubled, what is expected to the amount of heat released? ...

Solved • Aug 8, 2016

Endothermic & Exothermic Reactions

Q. Water vapor condensing to liquid water is what type of process? A) endothermic B) isotopic C) enthalpic D) exothermic 

Solved • Jul 28, 2016

Endothermic & Exothermic Reactions

Q. Consider the decomposition of liquid benzene, C6H6 (l), to gaseous acetylene, C2H2 (g):C6H6 (l) → 3 C2H2 (g)         ΔH = +630 kJ (d) If C6H6 (g) w...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Consider the decomposition of liquid benzene, C6H6 (l), to gaseous acetylene, C2H2 (g):C6H6 (l) → 3 C2H2 (g)         ΔH = +630 kJ (c) Which is more...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Consider the decomposition of liquid benzene, C6H6 (l), to gaseous acetylene, C2H2 (g):C6H6 (l) → 3 C2H2 (g)         ΔH = +630 kJ(a) What is the en...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Consider the combustion of liquid methanol, CH 3OH (l):CH3OH (l) + 3/2 O2 (g) → CO2 (g) + 2 H2O (l)     ΔH = -726.5 kJ(d) If the reaction were writ...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Consider the combustion of liquid methanol, CH 3OH (l):CH3OH (l) + 3/2 O2 (g) → CO2 (g) + 2 H2O (l)     ΔH = -726.5 kJ(c) Which is more likely to b...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Consider the combustion of liquid methanol, CH 3OH (l):CH3OH (l) + 3/2 O2 (g) → CO2 (g) + 2 H2O (l)     ΔH = -726.5 kJ(a) What is the enthalpy chan...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

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 =...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Consider the following reaction: CH3OH (g) → CO (g) + 2 H 2 (g)       ΔH = +90.7 kJ(a) Is heat absorbed or released in the course of this reaction?

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Without referring to tables, predict which of the following has the higher enthalpy in each case: (d) 1 mol N2 (g) at 100°C or 1 mol N2 (g) at 300°C.

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Without referring to tables, predict which of the following has the higher enthalpy in each case: (c) 1 mol H2 (g) and 0.5 mol O2 (g) at 25°C or 1 ...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Without referring to tables, predict which of the following has the higher enthalpy in each case: (b) 2 mol of hydrogen atoms or 1 mol of H2

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. Without referring to tables, predict which of the following has the higher enthalpy in each case: (a) 1 mol CO2 (s) or 1 mol CO2 (g) at the same te...

Solved • Jul 13, 2016

Endothermic & Exothermic Reactions

Q. When diluting concentrated H2SO4, the acid should be added to water because (A) concentrated sulfuric acid is a strong acid and can only be added ...

Solved • May 11, 2016

Endothermic & Exothermic Reactions

Q. When a material in a liquid state is vaporized and then condensed to a liquid, the steps in the process are, respectively, a) exothermic and exoth...

Solved • May 9, 2016

Endothermic & Exothermic Reactions

Q. When Na2S2O3• 3 H2O dissolves in water, the solution gets cold. Which diagram best represents the change in enthalpy for the contents of the flask?...

Solved • May 9, 2016

Endothermic & Exothermic Reactions

Q. Which of the following processes is endothermic? a) The freezing of water b) The combustion of gasoline c) The chemical reaction in a hot pack o...

Solved • Apr 20, 2016

Endothermic & Exothermic Reactions

Q. Consider the combustion of fuel and the analogous reaction the food undergoes as part of the metabolic processes: fuel/food + O2(g) → CO2(g) + H2O...

Solved • Mar 20, 2016

Endothermic & Exothermic Reactions

Q. How many of the following processes would be exothermic (ΔH < 0)? HCl(g) → H(g) + Cl(g) Br(g) + Br(g) → Br2(g) KI (s) → K + (g) + l  - (g) C...

Solved • Mar 16, 2016

Endothermic & Exothermic Reactions

Q.  When heat is absorbed by the surroundings from the system, the process is said to be ______________ , and the sign of Δq is____________? (circle o...

Solved • Mar 14, 2016

Endothermic & Exothermic Reactions

Q. Which of the following processes is expected to be endothermic? a) combustion of a hydrocarbon b) freezing of liquid N2 at its normal melting poi...

Solved • Feb 16, 2016

Endothermic & Exothermic Reactions

Q. When dry ice, CO2 (s), sublimes to the gas phase to form CO 2 (g).   a. The process is endothermic and heat is absorbed from the surroundings b....

Solved • Feb 12, 2016

Endothermic & Exothermic Reactions

Q. How many of the following processes would be exothermic (ΔH < 0)? HCl (g)  →  H (g) + Cl (g) Br (g) + Br (g) → Br 2 (g) KI (s) → K + (g) + l ...

Solved • Feb 12, 2016

Endothermic & Exothermic Reactions

Q. What can you say about the reaction if the ratio of the C=C double bond strength to the C-C single bond strength is less that two?

Solved • Feb 4, 2016

Endothermic & Exothermic Reactions

Q. We have seen many times in lecture that heat is given off in the combustion of hydrogen gas. Which of the following is responsible for the heat? a...

Solved • Feb 4, 2016

Endothermic & Exothermic Reactions

Q. Which one of the following processes is endothermic?a. 2 H2 (g) + O2 (g) → 2 H2O (g)b. H2O (g) → H 2O (l)c. CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g...

Solved • Feb 4, 2016

Endothermic & Exothermic Reactions

Q. When solid ice, H2O(s), undergoes fusion a) The process is endothermic and heat is absorbed from the surroundings. b) The process is endothermic ...

Solved • Feb 2, 2016