Physical Chemistry II Certification
Examination Questions and Correct
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Rationales 2026 Q&A | Instant
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1. Chemical kinetics is the study of:
A. Energy storage only
B. Chemical equilibrium only
C. Rates of chemical reactions
D. Molecular naming
Answer: C. Rates of chemical reactions
Rationale: Chemical kinetics examines how quickly reactions occur and the factors
affecting reaction rates.
2. The rate of a reaction is commonly expressed as a change in:
A. Temperature over time
B. Concentration over time
C. Pressure over volume
D. Energy over mass
Answer: B. Concentration over time
Rationale: Reaction rate measures how reactant or product concentration
changes with time.
,3. Increasing reactant concentration generally causes reaction rate to:
A. Decrease always
B. Remain constant
C. Increase
D. Become zero
Answer: C. Increase
Rationale: Higher reactant concentration increases the frequency of molecular
collisions.
4. Collision theory states that reactions occur when particles:
A. Have identical masses
B. Are at equilibrium
C. Collide with sufficient energy and proper orientation
D. Stop moving
Answer: C. Collide with sufficient energy and proper orientation
Rationale: Effective collisions require enough energy to overcome activation
energy and correct alignment.
5. The minimum energy required for a reaction to occur is called:
A. Enthalpy
B. Entropy
C. Activation energy
D. Free energy
Answer: C. Activation energy
Rationale: Activation energy is the energy barrier that reactants must overcome to
form products.
6. A catalyst increases reaction rate by:
,A. Increasing reactant concentration
B. Increasing product energy
C. Lowering activation energy
D. Changing equilibrium constant
Answer: C. Lowering activation energy
Rationale: Catalysts provide an alternative pathway with lower activation energy.
7. A catalyst affects the:
A. Equilibrium constant
B. Final product amount
C. Reaction rate
D. Chemical formula
Answer: C. Reaction rate
Rationale: Catalysts speed up both forward and reverse reactions without
changing equilibrium position.
8. The rate law relates reaction rate to:
A. Molecular weight
B. Reactant concentrations
C. Product color
D. Solution volume only
Answer: B. Reactant concentrations
Rationale: Rate laws describe how concentration affects reaction speed.
9. The overall order of a reaction is determined by:
A. Number of products
B. Reaction temperature
, C. Sum of rate law exponents
D. Molecular mass
Answer: C. Sum of rate law exponents
Rationale: Reaction order equals the total power of concentration terms in the
rate law.
10. A first-order reaction has a rate proportional to:
A. Concentration squared
B. Temperature only
C. One reactant concentration
D. Product concentration only
Answer: C. One reactant concentration
Rationale: First-order reactions have a rate law containing one concentration term
raised to the first power.
11. The integrated rate law for a first-order reaction is:
A. [A] = [A]₀ + kt
B. ln[A] = ln[A]₀ − kt
C. 1/[A] = kt
D. Rate = k[A]²
Answer: B. ln[A] = ln[A]₀ − kt
Rationale: First-order reactions show a linear relationship between ln
concentration and time.
12. The half-life of a first-order reaction depends on:
A. Initial concentration only
B. Rate constant
Examination Questions and Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Chemical kinetics is the study of:
A. Energy storage only
B. Chemical equilibrium only
C. Rates of chemical reactions
D. Molecular naming
Answer: C. Rates of chemical reactions
Rationale: Chemical kinetics examines how quickly reactions occur and the factors
affecting reaction rates.
2. The rate of a reaction is commonly expressed as a change in:
A. Temperature over time
B. Concentration over time
C. Pressure over volume
D. Energy over mass
Answer: B. Concentration over time
Rationale: Reaction rate measures how reactant or product concentration
changes with time.
,3. Increasing reactant concentration generally causes reaction rate to:
A. Decrease always
B. Remain constant
C. Increase
D. Become zero
Answer: C. Increase
Rationale: Higher reactant concentration increases the frequency of molecular
collisions.
4. Collision theory states that reactions occur when particles:
A. Have identical masses
B. Are at equilibrium
C. Collide with sufficient energy and proper orientation
D. Stop moving
Answer: C. Collide with sufficient energy and proper orientation
Rationale: Effective collisions require enough energy to overcome activation
energy and correct alignment.
5. The minimum energy required for a reaction to occur is called:
A. Enthalpy
B. Entropy
C. Activation energy
D. Free energy
Answer: C. Activation energy
Rationale: Activation energy is the energy barrier that reactants must overcome to
form products.
6. A catalyst increases reaction rate by:
,A. Increasing reactant concentration
B. Increasing product energy
C. Lowering activation energy
D. Changing equilibrium constant
Answer: C. Lowering activation energy
Rationale: Catalysts provide an alternative pathway with lower activation energy.
7. A catalyst affects the:
A. Equilibrium constant
B. Final product amount
C. Reaction rate
D. Chemical formula
Answer: C. Reaction rate
Rationale: Catalysts speed up both forward and reverse reactions without
changing equilibrium position.
8. The rate law relates reaction rate to:
A. Molecular weight
B. Reactant concentrations
C. Product color
D. Solution volume only
Answer: B. Reactant concentrations
Rationale: Rate laws describe how concentration affects reaction speed.
9. The overall order of a reaction is determined by:
A. Number of products
B. Reaction temperature
, C. Sum of rate law exponents
D. Molecular mass
Answer: C. Sum of rate law exponents
Rationale: Reaction order equals the total power of concentration terms in the
rate law.
10. A first-order reaction has a rate proportional to:
A. Concentration squared
B. Temperature only
C. One reactant concentration
D. Product concentration only
Answer: C. One reactant concentration
Rationale: First-order reactions have a rate law containing one concentration term
raised to the first power.
11. The integrated rate law for a first-order reaction is:
A. [A] = [A]₀ + kt
B. ln[A] = ln[A]₀ − kt
C. 1/[A] = kt
D. Rate = k[A]²
Answer: B. ln[A] = ln[A]₀ − kt
Rationale: First-order reactions show a linear relationship between ln
concentration and time.
12. The half-life of a first-order reaction depends on:
A. Initial concentration only
B. Rate constant
