Chapter 19 Chemical Thermodynamics

1. Chapter 19Chemical Thermodynamics Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten and Catherine J. Murphy Donna Narsavage Heald Siena College Loudonville, NY  2009, Prentice Hall

2. Which substance will have the highest entropy? • Butane • Isobutane • Pentane • Isopentane • Neopentane

3. Which substance will have the highest entropy? • Butane • Isobutane • Pentane • Isopentane • Neopentane

4. Which process will have a negative DS? • Dissolving a substance • Melting • Falling leaves • Oxidation of a metal • Decomposition of water into H2 and O2

5. Which process will have a negative DS? • Dissolving a substance • Melting • Falling leaves • Oxidation of a metal • Decomposition of water into H2 and O2

6. A reaction will be spontaneous at lower temperatures when the sign of DH and DS is

7. A reaction will be spontaneous at lower temperatures when the sign of DH and DS is

8. N2(g) + 3 H2(g) 2 NH3(g) DH° = –92.4 kJ/mol If the temperature of the reaction is decreased, what is the effect on the equilibrium constant and DG? • K increases; DG increases. • K decreases; DG decreases. • K increases; DG decreases. • K decreases; DG increases. • Temperature does not affect equilibrium or DG.

9. N2(g) + 3 H2(g) 2 NH3(g) DH° = –92.4 kJ/mol If the temperature of the reaction is decreased, what is the effect on the equilibrium constant and DG? • K increases; DG increases. • K decreases; DG decreases. • K increases; DG decreases. • K decreases; DG increases. • Temperature does not affect equilibrium or DG.

10. CaCO3(s) CaO(s) + CO2(g) Upon heating, limestone (CaCO3) decomposes to CaO and CO2. Speculate on the sign of DH and DS for this process.

11. CaCO3(s) CaO(s) + CO2(g) Upon heating, limestone (CaCO3) decomposes to CaO and CO2. Speculate on the sign of DH and DS for this process.