- What is chemical equilibrium?
a) When reactants are completely converted to products
b) When the rate of the forward reaction equals the rate of the reverse reaction
c) When the concentration of reactants is greater than products
d) When the concentration of products is greater than reactants
Answer: b - Which of the following statements is true at equilibrium?
a) The concentrations of reactants and products are equal
b) The concentrations of reactants and products are constant
c) The reaction stops
d) The rate of the reverse reaction is zero
Answer: b - In a reversible reaction, equilibrium is achieved when:
a) All reactants have been converted to products
b) The forward reaction stops
c) The rates of the forward and reverse reactions are equal
d) The reverse reaction stops
Answer: c - What happens to the equilibrium when a catalyst is added?
a) The equilibrium position shifts
b) The equilibrium constant changes
c) The rate of both forward and reverse reactions increases
d) The equilibrium is destroyed
Answer: c - Le Chatelier’s Principle is used to predict the effect of:
a) Catalysts on equilibrium
b) Temperature on equilibrium
c) Pressure on equilibrium
d) All of the above
Answer: d - When the temperature is increased for an endothermic reaction at equilibrium, the equilibrium will:
a) Shift to the right
b) Shift to the left
c) Remain unchanged
d) Decrease the reaction rate
Answer: a - In the reaction N2(g)+3H2(g)⇌2NH3(g)N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)N2(g)+3H2(g)⇌2NH3(g), increasing the pressure will:
a) Shift the equilibrium to the left
b) Shift the equilibrium to the right
c) Have no effect on equilibrium
d) Increase the rate of the reverse reaction
Answer: b - The equilibrium constant KcK_cKc is defined as:
a) The product of the concentrations of reactants
b) The ratio of the concentrations of products to reactants
c) The difference in concentrations of reactants and products
d) The sum of the concentrations of products
Answer: b - If Kc>1K_c > 1Kc>1, the reaction favors:
a) Reactants
b) Products
c) Both reactants and products equally
d) Neither reactants nor products
Answer: b - What is the unit of the equilibrium constant KpK_pKp for a reaction involving gases?
a) Molarity
b) Pressure
c) Volume
d) It depends on the reaction
Answer: d
