CHEMICAL EQUILIBRIUM

If a reaction has a very large equilibrium constant (K >> 1), what can be inferred?

• The reaction strongly favors the reactants

• The reaction strongly favors the products

• The reaction is at equilibrium

• The reaction proceeds at a very slow rate

For the reaction 2SO2(g)+O2(g)⇌2SO3(g), increasing the concentration of SO2​ will:

• Increase the equilibrium constant

• Decrease the equilibrium constant

• Shift equilibrium toward product formation

• Shift equilibrium toward reactant formation

A reaction at equilibrium has K=2.5K. If all reactant and product concentrations are doubled, what happens to K?

• It remains the same

• It doubles

• It halves

• It becomes squared

In an exothermic reaction, increasing temperature will:

• Increase K

• Decrease K

• Have no effect on K

• Reverse the reaction

A reaction has a small equilibrium constant (K < 1). This means that at equilibrium:

• Reactants are mostly converted to products

• The reaction is fast

• The reaction favors the reactants

• • The system is at dynamic equilibrium with equal reactant and product amounts

A catalyst is added to a reaction system at equilibrium. What happens to K?

• K increases

• K decreases

• K remains unchanged

• K depends on the catalyst concentration

For the reaction H2(g)+I2(g)⇌2HI(g), what happens to the equilibrium constant if the pressure is increased?

• It increases

• It decreases

• It remains unchanged

• It depends on the concentration of HI

Which of the following changes will NOT affect the position of equilibrium for a gaseous reaction?

• Changing pressure

• Adding a catalyst

• Changing temperature

• Changing reactant concentration

A reaction is at equilibrium with K=1.0K. If a reactant is removed, the reaction will:

• Shift toward products

• Shift toward reactants

• Maintain equilibrium

• Increase K

Which of the following statements about equilibrium constants is true?

• A large K always means the reaction is fast

• K changes when reactant concentrations change

• K is constant at a given temperature

• A small K means the reaction is spontaneous