AP Style Questions Unit 9 Part 1

Thermodynamics Multiple Choice Questions

1. What does entropy measure in a system?

a) Energy
b) Disorder
c) Temperature
d) Pressure

2. According to the second law of thermodynamics, what happens to the entropy of an isolated system?

a) Decreases
b) Increases
c) Remains constant
d) Fluctuates

3. Which equation combines enthalpy, temperature, and entropy to determine reaction favorability?

a) E = mc²
b) F = ma
c) ∆G = ∆H - T∆S
d) PV = nRT

4. What does a negative ΔG indicate about a reaction under standard conditions?

a) Non-spontaneous
b) Spontaneous
c) At equilibrium
d) Endothermic

5. Relative to what is absolute entropy measured?

a) Room temperature
b) Boiling point
c) Perfect crystal at 0 K
d) Standard pressure

6. How is entropy change calculated for a reaction?

a) Sum of reactants minus sum of products
b) Sum of products minus sum of reactants
c) Product of reactants divided by products
d) Difference in temperature

7. What typically characterizes exothermic reactions in terms of enthalpy change?

a) Positive ΔH
b) Zero ΔH
c) Negative ΔH
d) Variable ΔH

8. Which equation relates cell potential to concentration and temperature?

a) Gibbs Free Energy equation
b) Nernst equation
c) Ideal Gas Law
d) Arrhenius equation

9. What allows non-favored reactions to occur by pairing them with highly favored reactions?

a) Independent reactions
b) Coupled reactions
c) Reversible reactions
d) Spontaneous reactions

10. When does equilibrium occur in a chemical reaction?

a) When ΔG > 0
b) When ΔG < 0
c) When ΔG = 0
d) When ΔH = 0