1. A gas absorbs 10.0 J of heat and then performs 77.0 J of work. What is the change in internal energy of the gas?
Select one:
a. -67.0
b. 67.0 J
c. -87 J
d. 87 J
e. none of these
2. A system under constant external pressure undergoes a decrease in volume. What is the effect on the surroundings?
Select one:
a. Energy is transferred as pressure-volume work done on the surroundings.
b. Energy is transferred as pressure-volume work done by the surroundings on the system.
c. Energy is transferred as heat from the system to the surroundings.
d. Energy is transferred as heat from the surroundings to the system.
e. None of the above.
3. For the process 2Cl(g)→Cl2(g),For the process 2Cl(g)→Cl2(g),
Select one:
a. ΔH is + and ΔS is + for the reaction.ΔH is + and ΔS is + for the reaction.
b. ΔH is + and ΔS is =0 for the reaction.ΔH is + and ΔS is =0 for the reaction.
c. ΔH is - and ΔS is - for the reaction.ΔH is - and ΔS is - for the reaction.
d. ΔH is - and ΔS is + for the reaction.ΔH is - and ΔS is + for the reaction.
e. ΔH is + and ΔS is - for the reaction.
4. For which of the following processes would ΔS° be expected to be most negative?For which of the following processes would ΔS° be expected to be most negative?
Select one:
a. H2O(l)→H2O(s)H2O(l)→H2O(s)
b. NH3(g)+HCl(g)→NH4Cl(s)NH3(g)+HCl(g)→NH4Cl(s)
c. O2(g)+2H2(g)→2H2O(g)O2(g)+2H2(g)→2H2O(g)
d. N2O4(g)→2NO2(g)N2O4(g)→2NO2(g)
e. 2NH4NO3(s)→2N2(g)+O2(g)+4H2O(g)
5. Given the following, determine ΔS° at 298 K for the reaction below.Given the following, determine ΔS° at 298 K for the reaction below.
2NO(g)+O2(g)→2NO2(g); ΔS°=?2NO(g)+O2(g)→2NO2(g); ΔS°=?
Substance S° (J/(mol ⋅ K)) at 298 KNO(g) 210.9O2(g) 205.1NO2(g) 240.0Substance S° (J/(mol · K)) at 298 KNO(g) 210.9O2(g) 205.1NO2(g) 240.0
Select one:
a. 210.9 J/K210.9 J/K
b. -146.7 J/K-146.7 J/K
c. 421.7 J/K421.7 J/K
d. -421.7 J/K-421.7 J/K
e. +90.85 J/K
6. In which of the following scenarios is no change in the internal energy of the system possible?
Select one:
a. q= -wq= -w
b. q> 0,w> 0q> 0,w> 0
c. q= 0,w> 0q= 0,w> 0
d. q< 0,w= 0q< 0,w= 0
e. q< 0,w< 0q< 0,w< 0
7. The standard enthalpy of vaporization of Freon-10, CCl4CCl4, is 29.82 kJ/mol at its normal boiling point of 77°C. What is the change of entropy for 153.6 g of liquid Freon-10 when it vaporizes at its normal boiling point?
Select one:
a. 8.52×10-2J/K8.52×10-2J/K
b. 1.04×104J/K1.04×104J/K
c. 85.2 J/K85.2 J/K
d. 0.387 J/K0.387 J/K
e. 3.87×102J/K
8. What is the change in entropy when 6.46 g of water decomposes to form hydrogen gas What is the change in entropy when 6.46 g of water decomposes to form hydrogen gas and oxygen gas at 298 K?and oxygen gas at 298 K?
2H2O(l)→2H2(g)+O2(g); ΔS°=326.3J/K at 298 K2H2O(l)→2H2(g)+O2(g); ΔS°=326.3J/K at 298 K
Select one:
a. 58.5 J/K
b. 0.0785 J/K
c. 23.4 J/K
d. 11.7 J/K
e. 211 J/K
9. When 0.100 g of silicon is burned in excess oxygen to yield silicon dioxide at 298 K When 0.100 g of silicon is burned in excess oxygen to yield silicon dioxide at 298 K the change in entropy is -0.649 J/K. What is ΔS° for the reaction below?the change in entropy is -0.649 J/K. What is ΔS° for the reaction below? Si(s)+O2(g)→SiO2(s); ΔS°=?Si(s)+O2(g)→SiO2(s); ΔS°=?
Select one:
a. -182 J/K-182 J/K
b. -18.2 J/K-18.2 J/K
c. -2.18×10-3J/K-2.18×10-3J/K
d. -5.12×104J/K-5.12×104J/K
e. -182.4 J/K-182.4 J/K
10. Which of the following is true for the condensation of a gas?
Select one:
a. ΔS=0 and ΔH=0.ΔS=0 and ΔH=0.
b. ΔS<0 and ΔH<0.ΔS<0 and ΔH<0.
c. ΔS<0 and ΔH>0.ΔS<0 and ΔH>0.
d. ΔS>0 and ΔH>0.ΔS>0 and ΔH>0.
e. ΔS>0 and ΔH<0.