______ pts. out of 100 possible pts. = % = Name:

Advanced Chemistry: Test #6 (Kinetics & Equilibria)

Multiple Choice: Circle the letter to the left of the best answer. (3 pts. each)

1. If a reaction has a rate expression as follows: Rate = k [A][B]² , the rate of that reaction may be said to be:

a. zero order with respect to A

b. second order with respect to A

c. first order with respect to B

d. third order overall

e. none of the above

2. For the reaction shown above in problem 1, if the concentration of both A and B is doubled the rate of the reaction will go up by a factor of:

a. 2

b. 4

c. 6

d. 8

e. 12

3. Catalysts affect reaction rates by:

a. increasing the activation energy

b. increasing the energy of each collision

c. lowering the activation energy

d. increasing the concentration of the reactants

e. increasing the probability of collisions

4. Raising the temperature of a reaction system increases the rate of the reaction but does NOT increase the:

a. number of collisions

b. activation energy

c. average energy of each collision

d. number of collisions that exceed the activation energy

e. average velocity of each of the reactant molecules

5. If no data is available and the reaction mechanism is unknown, what would you write for the rate equation for the reaction in which propane (C₃H₈) reacts with oxygen gas to form carbon dioxide gas and water vapor? (3 pts.)

6. Carbon monoxide gas and hydrogen gas can react to form methanol gas (CH₃OH). At 275.0^oC, the equilibrium constant for this reaction is 8.776 x 10^-4 L²/mol².

a. If the equilibrium concentrations of CH₃OH and carbon monoxide are 0.124 mol/l and 3.56 mol/l, respectively, at 275.0^oC, what is the equilibrium concentration of the hydrogen? (9 pts.)

b. If the temperature is increased, what happens to the amount of methanol at equilibrium? (3 pts.)

c. If the pressure is increased, what happens to the amount of methanol at equilibrium? (3 pts.)

d. If a catalyst is added, what happens to the amount of methanol at equilibrium? (3 pts.)

e. If hydrogen is injected into the reaction container that holds the equilibrium mixture, what will have happened to the amount of carbon monoxide when equilibrium is regained? (3 pts.)

f. Is the above reaction exothermic or endothermic as stated? (3 pts.)

7. The following reaction is exothermic as written:

4 H₂O_(g) + 3 Fe_(s) Fe₃O_4(s) + 4H_2(g)

a. What will happen to the amount of H_2(g) in the container if the container is crushed to a smaller volume? (3 pts.)

b. What will happen to the amount of Fe_(s) in the container if the temperature is increased? (3 pts.)

c. What will happen to the amount of H_2(g) in the container if the amount of Fe_(s) is increased? (3 pts.)

8. A reaction occurs using the following mechanism:

1) A_(s) + 2C_(aq) D_(aq) + H_(aq) (fast)

2) D_(aq) + B_(aq) G_(aq) + 2T_(l) (very fast)

3) G_(aq) + X_(aq) A_(s) + B_(aq) (incredibly fast)

a. What is the net reaction? (3 pts.)

b. List any and all catalysts in the above mechanism. (3 pts.)

c. List any and all reaction intermediates in the above mechanism. (3 pts.)

d. What is the rate equation for the net reaction? (3 pts.)

9 a. Given the following data, determine the rate equation for the reaction: (8 pts.)

A + B C + D

[A] [B] Rxn Rate

0.20 M 0.30 M 0.20

0.20 M 0.60 M 1.60

0.20 M 0.90 M 5.40

0.40 M 0.30 M 0.40

0.60 M 0.30 M 0.60

b. What is the order of the reaction overall? (3 pts.)

10. How many grams of silver phosphate can be dissolved in 350.0 ml of water? (10 pts.)

11 a. Given the following data, determine the rate equation for the reaction: (8 pts.)

A + B C + D

[A] [B] Rxn Time

0.10 M 0.30 M 96.0 s

0.20 M 0.60 M 1.50 s

0.20 M 0.30 M 6.00 s

b. What would the reaction time be if the initial concentrations of both A and B were 0.50 M ? (4 pts.)

12. If 50.0 mL of 0.010 M NaCl is mixed with 100.0 mL of 0.50 M Pb(NO₃)₂, will a precipitate form? (You must prove your answer.) (8 pts.)