#1
Which statement describes chemical equilibrium?
The rate of the forward reaction is equal to the rate of the reverse reaction.
The concentration of reactants is higher than the concentration of products.
The reaction has come to a standstill.
The reaction is irreversible.
#2
Which statement is true regarding a system at equilibrium?
The concentrations of reactants and products are constant.
The rate of the forward reaction is greater than the rate of the reverse reaction.
The system has stopped reacting.
The concentration of products is higher than the concentration of reactants.
#3
Which statement accurately describes a dynamic equilibrium?
The reaction has stopped completely.
The rate of the forward reaction is always greater than the rate of the reverse reaction.
The concentrations of reactants and products remain constant over time.
The equilibrium constant changes with temperature.
#4
Which statement accurately describes a homogeneous equilibrium?
The reactants and products are in different physical states.
The reaction takes place in an open container.
All reactants and products are in the same physical state.
The rate of the forward reaction is greater than the rate of the reverse reaction.
#5
Which statement accurately describes the reaction quotient Q?
It represents the ratio of product concentrations to reactant concentrations at equilibrium.
It is the same as the equilibrium constant Kc for any given reaction.
It is calculated using initial concentrations of reactants and products.
It remains constant throughout the reaction.
#6
What does Le Chatelier's Principle state?
When a stress is applied to a system in dynamic equilibrium, the system adjusts to reduce the stress.
A system at equilibrium will stay at equilibrium regardless of external conditions.
The equilibrium constant remains constant regardless of changes in temperature or pressure.
The rate of a chemical reaction is proportional to the concentration of reactants.
#7
Which factor does NOT affect the position of equilibrium?
Temperature
Pressure
Catalyst
Initial concentration of reactants
#8
How does increasing the temperature affect an endothermic reaction at equilibrium?
It shifts the equilibrium towards the reactants.
It shifts the equilibrium towards the products.
It has no effect on the equilibrium position.
It depends on the concentration of reactants.
#9
Which of the following statements about the equilibrium constant (Kc) is correct?
Kc can change with temperature but not with pressure.
Kc is independent of the stoichiometry of the reaction.
Kc is always greater than 1 for exothermic reactions.
Kc is only applicable to homogeneous equilibria.
#10
What happens to the equilibrium position when a catalyst is added to a reaction at equilibrium?
The equilibrium position shifts to the left.
The equilibrium position shifts to the right.
The equilibrium position remains unchanged.
The equilibrium position becomes indeterminate.
#11
How does increasing the pressure affect the equilibrium position of a reaction involving gaseous reactants and products?
It shifts the equilibrium towards the side with fewer moles of gas.
It shifts the equilibrium towards the side with more moles of gas.
It has no effect on the equilibrium position.
It depends on the temperature of the system.
#12
How does increasing the concentration of a reactant affect the equilibrium position?
It shifts the equilibrium towards the reactants.
It shifts the equilibrium towards the products.
It has no effect on the equilibrium position.
It depends on the temperature of the system.
#13
What is the equilibrium constant expression for the reaction: 2A + 3B ⇌ 4C?
[C]^4 / [A]^2[B]^3
[A]^2[B]^3 / [C]^4
[A]^3[B]^2 / [C]^4
[C]^2 / [A]^4[B]^3
#14
Which statement best describes a heterogeneous equilibrium?
All reactants and products are in the same physical state.
Reactants and products are in different phases.
The reaction takes place in a closed container.
The rate of the forward reaction is equal to the rate of the reverse reaction.
#15
What is the effect of adding an inert gas at constant volume to a system at equilibrium?
It decreases the volume of the system.
It increases the pressure on the system.
It has no effect on the equilibrium position.
It decreases the temperature of the system.
#16
In the reaction N2(g) + 3H2(g) ⇌ 2NH3(g), if the volume of the container is decreased, what will happen to the concentration of NH3 at equilibrium?
It will decrease.
It will increase.
It will remain unchanged.
It depends on the initial concentrations.
#17
For the reaction CO(g) + H2O(g) ⇌ CO2(g) + H2(g), if the concentration of CO2 is increased, what happens to the concentrations of CO and H2O at equilibrium?
Both CO and H2O increase.
CO increases and H2O decreases.
CO decreases and H2O increases.
Both CO and H2O decrease.
#18
What is the effect of increasing the volume on a system at equilibrium for a reaction that involves a decrease in the number of moles of gas?
It shifts the equilibrium towards the side with fewer moles of gas.
It shifts the equilibrium towards the side with more moles of gas.
It has no effect on the equilibrium position.
It depends on the pressure of the system.
#19
For the reaction N2(g) + 3H2(g) ⇌ 2NH3(g), if the pressure is increased by decreasing the volume, what happens to the concentration of NH3 at equilibrium?
It increases.
It decreases.
It remains unchanged.
It depends on the initial concentrations.