Chapter 16: Energy and Chemical Change Practice Test
 1. How much heat is absorbed in the complete reaction of 3.00 grams of SiO2 with excess carbon in the reaction below?ΔH° for the reaction is +624.7 kJ. SiO2(g) + 3C(s) → SiC(s) + 2CO(g)
 a. 31.2 kJ b. 1.13 × 105 kJv c. 366 kJ d. 5.06 kJ
 2. Calculate the ΔG° for the reaction below. 2C2H2 (g) + 5O2 (g) → 4CO2 (g) + 2H2O(l) ΔG° (kJ/mol) 209.2 0 -394.4 -237.2
 a. -1409 kJ b. -1643 kJ c. -2470 kJ d. -2599 kJ
 3. A body in motion possesses kinetic energy because of its __________.
 a. position b. motion c. inertia d. composition
 4. Calculate the amount of heat absorbed by 10.0 grams of ice at -15.0°C as it is converted to liquid water at 50.0°C. The specific heat of H2O(s) = 2.09 J/(g•°C). The specific heat of H2O(l) = 4.18 J/(g•°C). The heat of fusion is 333 J/g.
 a. 2.83 kJ b. 0.676 kJ c. 0.170 kJ d. 5.73 kJ
 5. The same amount of heat is added to a 10-g sample of each of the following metals. If each metal is initially at 20.0°C, which metal will reach the highest temperature?
 a. copper 0.385 J/(g•°C) b. gold 0.129 J/(g•°C) c. calcium 0.653 J/(g•°C) d. beryllium 1.82 J/(g•°C)
 6. Calculate the entropy change for the reaction below. N2 (g) + 3H2 (g) → 2NH3(g) S° (J/mol•K) 191.5 130.6 192.3
 a. -198.7 J/K b. -129.7 J/K c. 76.32 J/K d. 303.2 J/K
 7. Chemical reactions and physical changes that absorb energy from their surroundings are __________.
 a. endothermic b. mesothermic c. exothermic d. isothermic
 8. For the reaction below, the enthalpy change is +624.7 kJ. How would you classify this reaction? SiO2(g) + 3C(s) → SiC(s) + 2CO(g)
 a. exothermic reaction, heat is lost from the system b. endothermic reaction, heat is gained by the system c. exothermic reaction, heat is gained by the system d. endothermic reaction, heat is lost from the system
 9. How much heat energy is liberated when 11.0 grams of manganese is used in the formation of Mn2O3? ΔHf° for Mn2O3 is -962.3 kJ/mol
 a. 460 kJ b. 289 kJ c. 192 kJ d. 96.3 kJ
 10. Given the following information, SO3 (g) + H2O(l) → H2SO4 (l) ΔH° = -133 kJ Pb(s) + PbO2 (s) + 2H2SO4(l) → 2PbSO4(s) + 2H2O(l) ΔH° = -509 kJ calculate the ΔH° for the reaction below. Pb(s) + PbO2 (s) + 2SO3 (g) → 2PbSO4 (s)
 a. -376 kJ b. -642 kJ c. +376 kJ d. -775 kJ
 11. If 5.0 grams of copper cools from 35.0°C to 22.6°C and loses 23.6 joules of heat, what is the specific heat of copper?
 a. 0.62 J/(g•°C) b. 0.38 J/(g•°C) c. 0.076 J/(g•°C) d. 3.8 × 102 J/(g•°C)
 12. From the following data, H2 (g) + Cl2 (g) → 2HCl(g) ΔH°v = -185 kJ 2H2 (g) + O2 (g) → 2H2O(g) ΔH° = -483.7 kJ calculate ΔH° for the following reaction. 4HCl(g) + O2 (g) → 2Cl2 (g) + 2H2O(g)
 a. +299 kJ b. -114 kJ c. +114 kJ d. -299 kJ
 13. Calculate the enthalpy for the reaction below 2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g) ΔHf° (kJ/mol) -206.0 0 -348.3 -296.8
 a. -270.6 kJ b. +270.6 kJ c. -878.2 kJ d. +878.2 kJ
 14. Which of the following substances has an enthalpy value of 0 at 298 K and 1 atmosphere of pressure?
 a. HCl(aq) b. NaOH(s) c. Na(s) d. CO2 (g)
 15. At one atmosphere pressure and the melting point of a substance, which statement is true about this general equation? solid 3 liquid
 a. ΔH = 0 for the process b. ΔG = 0 for the process c. Both ΔH and ΔS = 0 for the process d. ΔS = 0 for the process
 16. Calculate ΔH° for the following reaction. Fe3O4 (s) + CO(g) → 3FeO(s) + CO2 (g) ΔH° (kJ/mol) -1118 -110.5 -272 -393.5
 a. -263 kJ b. 54 kJ c. 19 kJ d. -50 kJ
 17. A process can never be spontaneous when it is _________.
 a. exothermic, and there is an increase in disorder b. endothermic, and there is an increase in disorder c. exothermic, and there is an increase in disorder d. endothermic, and there is a decrease in disorder
 18. In the chemical reaction between aqueous solutions of hydrochloric acid (HCl) and sodium hydroxide (NaOH), what is the chemical system?
 a. aqueous HCl and NaOH b. HCl + NaOH → NaCl + H2O c. HCl and water d. NaOH and water
 19. Which of the following occurs with an increase in entropy?
 a. twenty nickels taken from a box and arranged tails up on a table b. the reaction PCl3 (g) + Cl2 (g) → PCl5(g) c. precipitation of silver chloride from a solution of silver ions and chloride ions d. evaporation of carbon tetrachloride
 20. Which of the following processes occurs with a decrease in entropy?
 a. boiling water b. freezing of water c. sublimation of dry ice d. dissolving salt in water