HS-PS1-6: Equilibrium in Chemical Reactions

What does it mean when a chemical reaction reaches equilibrium?

• The forward reaction stops

• The concentrations of reactants and products are equal

• The rates of the forward and reverse reactions are equal

• No more products are being formed

Which of the following changes would increase the amount of product in an equilibrium reaction?

• Adding more reactants

• Decreasing the temperature for an endothermic reaction

• Increasing the pressure in a system where gases are not involved

• Removing a catalyst

According to Le Chatelier’s Principle, how will a system at equilibrium respond to a decrease in reactant concentration?

• Shift towards the products

• Shift towards the reactants

• No shift will occur

• The equilibrium constant will change

Which factor affects the equilibrium position of a chemical reaction?

• Temperature

• Pressure

• Concentration

• All of the above

If the temperature of an exothermic reaction at equilibrium is increased, what will happen?

• The system will shift toward the products

• The system will shift toward the reactants

• The equilibrium will not be affected

• The rate of reaction will decrease

For the reaction N2+3H2 2NH3, how will increasing pressure affect equilibrium?

• Shift toward reactants

• Shift toward products

• No change

• Stops the reaction

In a system at equilibrium, what happens if more product is added?

• The reaction shifts toward the reactants

• The reaction shifts toward the products

• The equilibrium constant changes

• The reaction stops

How does a catalyst affect equilibrium?

• Shifts the equilibrium to the right

• Shifts the equilibrium to the left

• Increases the rate of both the forward and reverse reactions

• Increases the amount of products formed

For the reaction 2SO2 + O2 2SO3 + Heat, which change will shift equilibrium toward the products?

• Increasing temperature

• Decreasing pressure

• Removing SO₃

• Adding SO₃

Which of the following will NOT affect the position of equilibrium?

• Temperature change

• Adding a catalyst

• Changing concentration of reactants

• Changing the pressure of a gas reaction