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 exothermic reaction: N2(g) + 3H2(g) ⇌ 2NH3(g), what will happen if the temperature is increased? (2023)
A.
The equilibrium will shift to the right
B.
The equilibrium will shift to the left
C.
No change in equilibrium
D.
The reaction will stop
Solution
According to Le Chatelier's principle, increasing the temperature of an exothermic reaction shifts the equilibrium to the left, favoring the reactants.
Correct Answer:
B
— The equilibrium will shift to the left
Q. For the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens to the equilibrium if the volume of the container is decreased? (2022)
A.
Equilibrium shifts to the left
B.
Equilibrium shifts to the right
C.
No effect on equilibrium
D.
Equilibrium constant changes
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 (2 moles of SO3).
Correct Answer:
B
— Equilibrium shifts to the right
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. For the reaction: A(g) + B(g) ⇌ C(g) + D(g), if the volume of the container is decreased, what will be the effect on the equilibrium? (2023)
A.
Shift to the left
B.
Shift to the right
C.
No effect
D.
Increase the concentration of A
Solution
Decreasing the volume increases the pressure. According to Le Chatelier's principle, the equilibrium will shift towards the side with fewer moles of gas. If there are more moles of gas on the left side, the equilibrium will shift to the left.
Q. If the concentration of a reactant is increased in a system at equilibrium, what will happen according to Le Chatelier's principle?
A.
The equilibrium will shift to the right.
B.
The equilibrium will shift to the left.
C.
The equilibrium will not change.
D.
The reaction will stop.
Solution
According to Le Chatelier's principle, if a change is made to a system at equilibrium, the system will adjust to counteract that change. Increasing the concentration of a reactant will shift the equilibrium to the right, favoring the formation of products.
Correct Answer:
A
— The equilibrium will shift to the right.
Q. In a reversible reaction at equilibrium, if the temperature is increased, what will happen to the equilibrium position if the reaction is exothermic? (2023)
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase the rate of reaction
Solution
For an exothermic reaction, increasing the temperature shifts the equilibrium position to the left, favoring the reactants, as the system tries to absorb the added heat.
Q. In a reversible reaction at equilibrium, which of the following statements is true?
A.
The rate of the forward reaction is equal to the rate of the reverse reaction.
B.
The concentration of reactants is greater than products.
C.
The reaction has stopped completely.
D.
The temperature remains constant.
Solution
At equilibrium, the rate of the forward reaction equals the rate of the reverse reaction, which means the concentrations of reactants and products remain constant over time.
Correct Answer:
A
— The rate of the forward reaction is equal to the rate of the reverse reaction.
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 products is increased, what will happen to the equilibrium position? (2021)
A.
Shift to the left
B.
Shift to the right
C.
No change
D.
Depends on temperature
Solution
According to Le Chatelier's principle, increasing the concentration of products will shift the equilibrium position to the left to counteract the change.
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 a reversible reaction, if the concentration of the reactants is increased, what will happen to the position of equilibrium? (2023)
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, favoring the formation of products.
Q. In the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g), what happens to the equilibrium when the volume of the container is decreased? (2023)
A.
Equilibrium shifts to the left
B.
Equilibrium shifts to the right
C.
No change in equilibrium
D.
Equilibrium shifts to the side with more moles
Solution
According to Le Chatelier's principle, decreasing the volume increases the pressure, and the equilibrium will shift towards the side with fewer moles of gas. In this case, the right side has 2 moles of SO3 compared to 3 moles on the left, so the equilibrium shifts to the right.
Correct Answer:
B
— Equilibrium shifts to the right
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 A(g) + B(g) ⇌ C(g) + D(g), if the temperature is increased, what will be the effect on the equilibrium if the reaction is exothermic? (2020)
A.
The equilibrium shifts to the left
B.
The equilibrium shifts to the right
C.
No effect on the equilibrium
D.
The reaction rate increases
Solution
For an exothermic reaction, increasing the temperature shifts the equilibrium to the left (towards the reactants) to absorb the added heat, according to Le Chatelier's principle.
Correct Answer:
A
— The equilibrium shifts to the left
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
