Equilibrium Practice

1. If the equilibrium is established by initially adding 0.10 mol each of A and B to a 1L container, then which ofthefollowing must be true once the mixture achievesequilibrium? A +2B<>2C K =320 a. [A] =[B] b. [A] = [B] =[C] c. [B] =2[C] d. [A] >[B] e. [A] <[B]

d

1. The equilibrium constant for the formation of hydrogen iodide from hydrogen and iodine is 45 at a certain temperature. H2(g) + I2(s)<> 2HI(g) K =45 Which of the following is true regarding this equilibrium? I. The reaction is product favored. II. The reaction is reactant favored. III. Equilibrium lies to the right. IV. Equilibrium lies to the left.

I and III

1. The equilibrium constant for the acid ionization of mercaptoethanol (HSCH2CH2OH) is 1.91 x10-10. HSCH2CH2OH(aq) <> H+(aq) +SCH2CH2OH-(aq) K = 1.91 x10-10 Which of the following statements is true regarding thisequilibrium? I. The reaction is product favored. II. The reaction is reactant favored. III. Equilibrium lies far to the right. IV. Equilibrium lies far to the left.

II and IV

1. An equilibrium that strongly favors products has a. A value of K<<1. b. A value of K>>1. c. A value of Q>>1. d. A value of Q<<1. e. K =Q.

b

1. If the reaction quotient Q has a smaller value than the related equilibrium constant,K, a. the reaction is atequilibrium. b. the reaction is not at equilibrium, and will make more products at the expense of reactants. c. the reaction is not at equilibrium, and will make more reactants at the expense of products. d. the value of K will decrease until it is equal toQ.

b

1. Which of the following are equal for a chemical system at equilibrium? If all are equal, answer E. a. the concentrations of reactant and products are equal b. the rate constants for the forward and reverse reactions are equal c. the time that a particular atom or molecule spends as a reactant and product are equal d. the rate of the forward and reverse reaction e. all of the above are equal

b and d

1. If the reaction quotient Q has a larger value than the related equilibrium constant,K, a. the reaction is at equilibrium. b. the reaction is not at equilibrium, and will make more products at the expense of reactants. c. the reaction is not at equilibrium, and will make more reactants at the expense of products. d. the value of K will increase until it is equal toQ.

c

1. Which of the following is true regarding the concentration of products, for a chemical reaction that is already at equilibrium, assuming no disruptions to the equilibrium? a. The concentrations of products will not change because there are no more reactants. b. The concentrations of products will not change because the limiting reagent is gone. c. The concentrations of products will not change because the forward and reverse rates are equal. d. The concentrations of products will change continually because of reversibility.

c

1. Which of the following is true for a chemical reaction at equilibrium? a. only the forward reaction stops b. only the reverse reaction stops c. both the forward and reverse reactions stop d. the rate constants for the forward and reverse reactions are equal e. the rates of the forward and reverse reactions are equal

d and e

1. A chemical equilibrium may be established by starting a reaction with a. Reactants only. b. Products only. c. equal quantities of reactants and products. d. any quantities of reactants and products. e. all the above

e