Chemical Equilibrium Y12

What is the definition of a reversible reaction?

• A reaction that only goes forward

• A reaction that only goes backward

• A reaction where reactants and products are in equilibrium

• A reaction that cannot reach equilibrium

What does a dynamic equilibrium mean?

• The concentrations of reactants and products are different

• The rate of the forward reaction equals the rate of the backward reaction

• The rate of the forward reaction is less than the rate of the backward reaction

• The rate of the forward reaction is greater than the rate of the backward reaction

What is required for a reaction to reach equilibrium?

• A high temperature

• A closed system

• A low pressure

• An open system

According to Le Chatelier's principle, what happens if the concentration of a reactant is increased?

• Equilibrium shifts to the left

• Equilibrium shifts to the right

• Equilibrium remains unchanged

• The reaction stops

What happens to equilibrium if the pressure is increased?

• It remains unchanged

• It shifts to the side with fewer gas particles

• It shifts to the side with equal gas particles

• It shifts to the side with more gas particles

What is the effect of increasing temperature on an exothermic reaction?

• Equilibrium shifts to the left

• The reaction rate decreases

• Equilibrium shifts to the right

• Equilibrium remains unchanged

What is the effect of a catalyst on the position of equilibrium?

• It shifts equilibrium to the right

• It shifts equilibrium to the left

• It has no effect on the position of equilibrium

• It stops the reaction

What is the equilibrium constant (KC) expression for the reaction aA + bB ⇌ cC + dD?

• [A]^a [C]^c / [B]^b [D]^d

• [B]^b [D]^d / [A]^a [C]^c

• [A]^a [B]^b / [C]^c [D]^d

• [C]^c [D]^d / [A]^a [B]^b

What happens to KC if the temperature change causes equilibrium to shift to the right?

• KC decreases

• KC remains unchanged

• KC increases

• KC becomes zero

In the reaction 2NO2 ⇌ N2O4, what color change occurs when placed in a warm water bath?

• The gas turns red

• The gas turns yellow

• The gas turns brown

• The gas turns colorless