Equilibrium Practice Test MCQ's

When the substances in the exothermic equation below are at equilibrium at pressure P and temperature T, the equilibrium can be shifted to favor the products by

• increasing the pressure in the reaction vessel while keeping the temperature constant

• increasing the pressure by adding an inert gas such as argon

• decreasing the temperature

• allowing some hydrogen gas to escape at constant P and T

• adding a catalyst

Tags

NGSS.HS-PS1-6

When 0.60 mole of A and 0.75 mole of B are placed in an evacuated 1.00 L flask, the reaction represented above occurs. After the reactants and the product reach equilibrium and the initial temperature is reduced, the flask is found to contain 0.30 mole of product C. Based on these results, the equilibrium constant, K_c for the reaction is

• 0.60

• 0.90

• 1.7

• 3.4

• 6.0

Tags

NGSS.HS-PS1-7

• 0.25

• 1

• 5

• 25

Which of the following systems would NOT experience a change in the number of moles of the substances present at equilibrium when the volume of the system is changed at constant temperature?

• SO3(g) + NO(g) ⇌ SO2(g) + 1/2 N2

• O2(g) + 2 H2(g) ⇌ 2 H2O(g)

• N2(g) + 2 O2(g) ⇌ 2 NO2(g)

• N2O4(g) ⇌ 2 NO2(g)

• CH4(g) + 2 O2(g) ⇌ CO2(g) + 2 H2O(g)

• More product will form.

• More reactant will form.

• The quantities placed in the reaction are equilibrium quantities.

• There is not enough information to determine if the reaction is at equilibrium or not.

Tags

NGSS.HS-PS1-5

Which of the following changes alone would cause a decrease in the value of Kc for the exothermic reaction represented above?

• Removing NH3

• Increasing the temperature

• Adding an inert gas such as argon

• Adding more hydrogen gas at constant temperature

• Adding a catalyst

Tags

NGSS.HS-PS1-4

Consider the equilibrium above. Which of the following changes will increase the concentration of SO3(g)?

• Increasing the concentration of O2(g)

• Increasing the pressure in the reactant vessel at constant temperature

• Increasing the mass of SO3 present

• Adding a catalyst

• Decreasing the temperature

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-6

Consider the reaction system, NiO(s) + H2(g) ⇌ Ni(s) + H2O(g). The equilibrium constant expression is

• Kc = [Ni][H2O] / [NiO][H2]

• Kc = [Ni] / [NiO][H2]

• Kc = 1 / [NiO][H2]

• Kc = 1 / [H2]

• Kc = [H2O] / [H2]

Tags

NGSS.HS-PS1-7

Given the equilibrium, 2SO2(g) + O2(g) ⇌ 2SO3(g). If this equilibrium is established by beginning with equal number of moles of SO2 and O2 in an empty 1.0 L bulb, then the following must be true at equilibrium:

• A

• B

• C

• D

• E

Tags

NGSS.HS-PS1-7