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Endothermic & Exothermic Reactions Solutions Library

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Endothermic & Exothermic Reactions

Q. Determine whether each process is exothermic or endothermic and indicate the sign of ΔΗ. a. dry ice evaporating b. a sparkler burning c. the reacti...

Solved • Jun 16, 2020

Endothermic & Exothermic Reactions

Q. An exothermic reaction causes the surroundings to A. warm up. B. become acidic. C. expand. D. decrease its temperature.E. release CO2.

Solved • Jun 16, 2020

Endothermic & Exothermic Reactions

Q. Water being turned into ice cubes in a freezer is an example of ___________ (endothermic or exothermic) process, and ∆H will be ___________. (posit...

Solved • May 1, 2020

Endothermic & Exothermic Reactions

Q. Based on relative bond strengths, classify these reactions as endothermic (energy absorbed) or exothermic (energy released ).

Solved • May 1, 2020

Endothermic & Exothermic Reactions

Q. 4Al(s) + 3 O2(g)→2Al2O3(s) q=-3351kJ is ____ and therefore heat is ______ by the reaction.

Solved • Apr 30, 2020

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 • Apr 20, 2020

Endothermic & Exothermic Reactions

Q. For a reaction to be endothermic, which of the following relationships is valid?a)  The energy required to break bonds is greater than the energy i...

Solved • Apr 14, 2020

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) 2 H(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. Classify each process as endothermic or exothermic.a. gasoline burning in an engineb. steam condensing on a mirrorc. water boiling in a pot

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. What is the sign of ΔH for each process.a. gasoline burning in an engineb. steam condensing on a mirrorc. water boiling in a pot

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. You may want to reference (Pages 267 - 270) Section 6.6 while completing this problem.Identify each process as endothermic or exothermic and indica...

Solved • Nov 12, 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. Which process is endothermic?a) the evaporation of water from the skinb) the burning of candle waxc) the oxidation of iron in a chemical hand warme...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. In an exothermic reaction, the reactants lose energy and the reaction feels hot to the touch. Explain why the reaction feels hot even though the re...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Which of the following expressions describes the heat evolved in a chemical reaction when the reaction is carried out at constant pressure?a. ΔE - ...

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

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

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. During an energy exchange, a chemical system absorbs energy from its surroundings. What is the sign of ΔEsys for this process? Explain.

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Explain the difference between an exothermic and an endothermic reaction.

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Explain the difference between an exothermic and an endothermic reaction. Give the sign of ΔH for each type of reaction.

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. Why does the reaction mixture undergo an increase in temperature even though energy is emitted?

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. From a molecular viewpoint, where does the energy absorbed in an endothermic chemical reaction go?

Solved • Nov 12, 2018

Endothermic & Exothermic Reactions

Q. Why does the reaction mixture undergo a decrease in temperature even though energy is absorbed?

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. Specific heat of water.Is the process shown in the figure endothermic or exothermic?

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. You may want to reference (Pages 191 - 192) Section 5.8 and Appendix C (Pages 1088 - 1091) while completing this problem.It is interesting to compa...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Without doing any calculations, predict the sign of ΔH for each of the following reactions:(a) NaCl(s) → Na+(g) + Cl-(g)

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Without doing any calculations, predict the sign of ΔH for each of the following reactions:(a) 2NO2(g) → N2O4(g)

Solved • Oct 31, 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. Liquid propane in the tank, C3H8, vaporizes and mixes with air as it escapes through the nozzle. The combustion reaction of C3H8 and O2 produces 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. A chemical reaction that gives off heat to its surroundings is said to be ____________ and has a ____________ value of H.

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Consider the conversion of compound A into compound B : A  →  B. For both compounds A and B, ΔH˚f > 0. Suppose the overall reaction is exothermi...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

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

Endothermic & Exothermic Reactions

Q. You may want to reference(Pages 166 - 172)Section 5.2 while completing this problem.A 100.0-g bar of gold is heated from 25˚C to 50˚C during which ...

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. 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

Endothermic & Exothermic Reactions

Q. The methane molecule, CH4, has the geometry shown in following figure. Imagine a hypothetical process in which the methane molecule is "expanded," ...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. The methane molecule, CH4, has the geometry shown in following figure. Imagine a hypothetical process in which the methane molecule is "expanded," ...

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. Consider the following unbalanced oxidation-reduction reactions in aqueous solution:Ag+(aq) + Li(s) → Ag(s) + Li+(aq)Fe(s) + Na+(aq) → Fe2+(aq) + N...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. You may want to reference (Pages 177 - 178) Section 5.4 while completing this problem.Without referring to tables, predict which of the following h...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Consider the combustion of liquid methanol, CH3OH(l): CH3OH(l) + 3/2 O2 (g) → CO2(g) + 2 H2O(l), ΔH = –726.5kJWhat is the enthalpy change for the r...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Consider the combustion of liquid methanol, CH3 OH(l): CH3OH(l) + 3/2 O2(g) → CO2(g) + 2 H2O(l), ΔH = –726.5kJWhich is more likely to be thermodyna...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Consider the combustion of liquid methanol, CH3 OH(l): CH3OH(l) + 3/2 O2(g) → CO2(g) + 2 H2O(l), ΔH = –726.5kJIf the reaction were written to produ...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

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

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Consider the decomposition of liquid benzene, C6H6(l), to gaseous acetylene, C2H2(g): C6H6(l) → 3 C2H2(g), ΔH = +630 kJWhich is more likely to be t...

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. Consider the decomposition of liquid benzene, C6H6(l), to gaseous acetylene, C2H2(g): C6H6(l) → 3 C2H2(g), ΔH = +630 kJIf C6H6(g) were consumed ins...

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. Determine whether the process is endothermic or exothermic.A system releases 856 kJ of heat to the surroundings and has 788 kJ of work done on it b...

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. Consider the energy diagram shown in the figure .If there is no work associated with the process, is it exothermic or endothermic?

Solved • Oct 31, 2018

Endothermic & Exothermic Reactions

Q. The contents of the closed box in each of the illustrations  represent a system, and the arrows show the changes to the system during some process....

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