CHEM 103 Module 5 | General Chemistry I with Lab Exam Q&A | Portage Learning

CHEM 103 Module 5 | General Chemistry I with Lab Exam Q&A | Portage
Learning
Here are 100 original practice questions for CHEM 103 Module 5 | Chemical
Equilibrium, Kinetics, and Redox. These are original review items and are not
official exam questions.


Question 1:
A nurse is teaching about reversible reactions in the body. Which statement
best describes chemical equilibrium?
A. The forward reaction stops completely.
B. The rates of the forward and reverse reactions are equal.
C. Only the reverse reaction occurs.
D. Equilibrium can occur only in a closed system.

Correct answer:
B
Rationale:
At equilibrium, the forward and reverse reactions continue at equal rates, so
concentrations remain constant.


Question 2:
In the reaction Hb + O₂ ⇌ HbO₂, what happens when the partial pressure of
oxygen increases?
A. Equilibrium shifts to the left.
B. Equilibrium shifts to the right.
C. No shift occurs.
D. Hemoglobin dissociates.

Correct answer:
B
Rationale:
Increasing O₂ concentration shifts equilibrium toward HbO₂ formation.

,Question 3:
A client with carbon monoxide poisoning has increased CO binding to
hemoglobin. How does this affect the Hb + O₂ ⇌ HbO₂ equilibrium?
A. Shifts right, increasing O₂ delivery.
B. Shifts left, reducing O₂ delivery.
C. No effect on equilibrium.
D. Increases oxygen release to tissues.

Correct answer:
B
Rationale:
CO binds hemoglobin with high affinity, reducing HbO₂ formation and shifting
equilibrium left.


Question 4:
Which expression correctly represents the equilibrium constant for N₂ + 3H₂ ⇌
2NH₃?
A. K = [NH₃]² / ([N₂][H₂]³)
B. K = ([N₂][H₂]³) / [NH₃]²
C. K = [NH₃] / ([N₂][H₂])
D. K = [N₂][H₂] / [NH₃]

Correct answer:
A
Rationale:
K equals products raised to coefficients over reactants raised to coefficients.


Question 5:
A reaction has Q < K. What will happen?
A. Reaction shifts left.
B. Reaction shifts right.
C. Reaction is at equilibrium.

,D. Reaction stops. Correct answer: B

Rationale:
When Q < K, the forward reaction is favored until Q = K.


Question 6:
A reaction has K > 1. At equilibrium, which is favored?
A. Reactants
B. Products
C. Neither
D. Equal amounts Correct answer: B

Rationale:
K > 1 means products are favored at equilibrium.


Question 7:
A reaction has K < 1. At equilibrium, which is favored?
A. Reactants
B. Products
C. Neither
D. Equal amounts Correct answer: A

Rationale:
K < 1 means reactants are favored at equilibrium.


Question 8:
How does a catalyst affect equilibrium?
A. Shifts equilibrium right.
B. Shifts equilibrium left.
C. Speeds attainment of equilibrium without shifting it.
D. Changes K. Correct answer: C

Rationale:

, Catalysts lower activation energy and speed equilibrium but do not change K or
position.


Question 9:
For an exothermic reaction, increasing temperature will:
A. Shift equilibrium right.
B. Shift equilibrium left.
C. Have no effect.
D. Increase K.

Correct answer:
B
Rationale:
Adding heat to an exothermic reaction shifts equilibrium toward reactants.


Question 10:
For a reaction with more gas moles on the reactant side, increasing pressure
will:
A. Shift equilibrium right.
B. Shift equilibrium left.
C. Have no effect.
D. Change K. Correct answer: A

Rationale:
Increasing pressure shifts equilibrium toward the side with fewer gas moles.


Question 11:
Increasing volume for a gas-phase equilibrium will:
A. Shift toward fewer gas moles.
B. Shift toward more gas moles.
C. Have no effect.
D. Change K. Correct answer: B