AP CHEMISTRY
Week 8 Problem Set
Solutions
, AP Chemistry Week 8
Problem Set Solution
Multiple Choice Questions
Question 1: Which of the following equations represents a reaction for which the
standard entropy change is positive (∆S⁰ > 0)?
A) 3O2(g) 2O3(g)
B) 2H2(g) + O2(g) 2H2O(l)
C) CaCO3(s) CaO(s) + CO2(g)
D) I2(g) + 2K(s) 2KI(s)
Answer:
C. Option C shows an increase in the number of molecules and one of the products is a
gas.
Option A: Decrease in number of gas particles
Option B: 2 molecules to 1 molecule. Also, go from gas (high entropy state) to
liquid (low entropy state).
Option D: Reaction reduces the number of molecules and produce a solid (low
entropy state)
Question 2: On the basis of the information below, the dissolution of FeF2 (s) in acidic
solution is
A) thermodynamically favorable, because K2 > 1
02
Week 8 Problem Set
Solutions
, AP Chemistry Week 8
Problem Set Solution
Multiple Choice Questions
Question 1: Which of the following equations represents a reaction for which the
standard entropy change is positive (∆S⁰ > 0)?
A) 3O2(g) 2O3(g)
B) 2H2(g) + O2(g) 2H2O(l)
C) CaCO3(s) CaO(s) + CO2(g)
D) I2(g) + 2K(s) 2KI(s)
Answer:
C. Option C shows an increase in the number of molecules and one of the products is a
gas.
Option A: Decrease in number of gas particles
Option B: 2 molecules to 1 molecule. Also, go from gas (high entropy state) to
liquid (low entropy state).
Option D: Reaction reduces the number of molecules and produce a solid (low
entropy state)
Question 2: On the basis of the information below, the dissolution of FeF2 (s) in acidic
solution is
A) thermodynamically favorable, because K2 > 1
02
