Q. For the exothermic reaction A + B ⇌ C + heat, what will happen if the temperature is increased? (2020)
A.Equilibrium will shift to the right
B.Equilibrium will shift to the left
C.No change in equilibrium
D.Equilibrium will shift to the center
Solution
For an exothermic reaction, increasing the temperature shifts the equilibrium to the left, favoring the reactants, as the system tries to absorb the added heat.
Correct Answer: B — Equilibrium will shift to the left
Q. For the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens to the equilibrium position if SO3 is removed from the system? (2023)
A.The equilibrium shifts to the left
B.The equilibrium shifts to the right
C.The equilibrium remains unchanged
D.The reaction stops
Solution
Removing SO3 will decrease its concentration, causing the system to shift to the right to produce more SO3 in order to re-establish equilibrium, according to Le Chatelier's principle.
Correct Answer: B — The equilibrium shifts to the right
Q. For the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what will happen if the volume of the container is increased? (2020) 2020
A.Equilibrium shifts to the right
B.Equilibrium shifts to the left
C.No change in equilibrium
D.Reaction stops
Solution
Increasing the volume decreases the pressure, and according to Le Chatelier's principle, the equilibrium will shift to the side with more moles of gas, which is the left side in this case.
Correct Answer: B — Equilibrium shifts to the left
Q. For the reaction N2(g) + 3H2(g) ⇌ 2NH3(g), what happens to the equilibrium if the volume of the container is decreased? (2020)
A.Equilibrium shifts to the right
B.Equilibrium shifts to the left
C.No change in equilibrium
D.Equilibrium shifts to the side with more moles
Solution
Decreasing the volume increases the pressure, and according to Le Chatelier's principle, the equilibrium will shift to the side with fewer moles of gas, which is the right side in this case.
Correct Answer: A — Equilibrium shifts to the right
Q. For the reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens to the equilibrium position if the volume of the container is decreased? (2020)
A.Shifts to the left
B.Shifts to the right
C.No change
D.Depends on temperature
Solution
Decreasing the volume increases the pressure, and according to Le Chatelier's principle, the equilibrium will shift towards the side with fewer moles of gas, which is the right side in this case.
Q. For the reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g), what will happen if the volume of the container is increased? (2020)
A.Equilibrium shifts to the right
B.Equilibrium shifts to the left
C.No change in equilibrium
D.Equilibrium shifts to the center
Solution
Increasing the volume decreases the pressure, and according to Le Chatelier's principle, the equilibrium will shift to the side with more moles of gas, which is the left side in this case.
Correct Answer: B — Equilibrium shifts to the left
Q. In a reversible reaction, if the concentration of products increases, what happens to the rate of the forward reaction? (2021)
A.It increases
B.It decreases
C.It remains constant
D.It becomes zero
Solution
According to Le Chatelier's principle, if the concentration of products increases, the system will shift to the left, decreasing the rate of the forward reaction.
Q. In a reversible reaction, if the concentration of reactants is increased, what will happen to the position of equilibrium? (2021)
A.It will shift to the right
B.It will shift to the left
C.It will remain unchanged
D.It will shift to the center
Solution
According to Le Chatelier's principle, increasing the concentration of reactants will shift the equilibrium position to the right to favor the formation of products.
Q. In a reversible reaction, if the concentration of reactants is increased, what will happen to the equilibrium position? (2021)
A.It will shift to the right
B.It will shift to the left
C.It will remain unchanged
D.It will shift to the center
Solution
According to Le Chatelier's principle, if the concentration of reactants is increased, the equilibrium will shift to the right to favor the formation of products.
Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what will happen if the volume of the container is increased? (2023)
A.Shift to the right
B.Shift to the left
C.No change
D.Increase in temperature
Solution
According to Le Chatelier's principle, increasing the volume of the container decreases the pressure. The equilibrium will shift towards the side with more moles of gas, which is the left side (2 moles of SO2 + 1 mole of O2).
Q. In the reaction CO(g) + 2H2(g) ⇌ CH3OH(g), what effect does increasing the temperature have if the reaction is exothermic? (2020)
A.Shifts equilibrium to the right
B.Shifts equilibrium to the left
C.No effect on equilibrium
D.Increases the rate of reaction
Solution
For an exothermic reaction, increasing the temperature shifts the equilibrium to the left, favoring the reactants, as the system tries to absorb the added heat.
Correct Answer: B — Shifts equilibrium to the left
Q. What is the equilibrium constant (Kc) for the reaction 2A + B ⇌ C? (2022)
A.Kc = [C] / ([A]^2[B])
B.Kc = [A]^2[B] / [C]
C.Kc = [B] / ([A]^2[C])
D.Kc = [C] / ([B][A])
Solution
The equilibrium constant Kc is defined as the concentration of the products raised to the power of their coefficients divided by the concentration of the reactants raised to the power of their coefficients. For the reaction 2A + B ⇌ C, Kc = [C] / ([A]^2[B]).
Q. What is the equilibrium constant (Kc) for the reaction: A + B ⇌ C + D? (2022)
A.Kc = [C][D]/[A][B]
B.Kc = [A][B]/[C][D]
C.Kc = [C][D][A][B]
D.Kc = [A][B][C][D]
Solution
The equilibrium constant Kc is defined as the ratio of the concentrations of the products to the reactants, each raised to the power of their coefficients in the balanced equation.
Q. Which of the following factors does NOT affect the position of equilibrium in a chemical reaction? (2021)
A.Concentration of reactants
B.Temperature
C.Pressure
D.Nature of the reactants
Solution
The nature of the reactants does not affect the position of equilibrium. Changes in concentration, temperature, and pressure can shift the equilibrium position according to Le Chatelier's principle.
