AP MCQ 05ABCDEFGHIJK PART 3 Question 01: Which of the following is a rate law, where the units of rate are equal to the units of the rate constant? Rate = k [A]0 Rate = k [A] Rate = k [A] [B] Rate = k [A] [B] [C]0 Question 02: Which answer choice correctly matches the integrated rate law shown below? 1/[A]t = k t + 1/[A]0 A zero order reaction where a plot of 1/[A]t (y-axis) versus t (x-axis) will yield a straight line with slope = k A first order reaction where a plot of 1/[A]t (y-axis) versus t (x-axis) will yield a straight line with slope = k A first order reaction where a plot of 1/[A]t (y-axis) versus t (x-axis) will yield a straight line with slope = -k A second order reaction where a plot of 1/[A]t (y-axis) versus t (x-axis) will yield a straight line with slope = k Question 03: A proposed mechanism for a given chemical reaction is given below. STEP 1 (fast) A + B → J STEP 2 (slow) J + A → C + F STEP 3 (fast) F + A → C + D Which combination of statements is consistent with the data above? Rate = k [A]2 [B] and the overall reaction is 3A + B → 2C + D Rate = k [A] [B] and the overall reaction is 3A + B → 2C + D Rate = k [A]2 [B] and the overall reaction is 3A + B → 2C + D + F + J Rate = k [A]3 [B] and the overall reaction is 3A + B → 2C + D Questions 04-06: Questions 4-6 relate to the popular demonstration called “Elephant’s Toothpaste”, in which the mechanism is believed to be as follows. STEP 1 H2O2 + I- → H2O + OI- STEP 2 H2O2 + OI- → H2O + O2 + I- Question 04: Which species is the catalyst in the reaction? H2O2 I- H2O OI- Question 05: Which species is an intermediate? H2O2 I- H2O OI- Question 06: Which chemical equation consistent with the mechanism provided? 2H2O2 → 2H2O + O2 2H2O2 + I- → 2H2O + O2 ½H2O2 + I- → H2O + O2 ½H2O2 + I- → H2O + OI- + O2 Questions 07-10: A reaction of the reactants A and B, to produce products X and Y, can be summarized as; 3A + 2B → 2X + Y The kinetics of the reaction are studied and data collected. Use the data in the table below to answer Questions 07-10. Question 07: What is the rate law for the reaction? Rate = k [A] [B]2 Rate = k [A]2 [B]2 Rate = k [B] Rate = k [B]2 Question 08: What is the value of the rate constant (with correct units)? 2 x 10-3M-1sec-1 2 x 10-3M-2sec-1 8 x 10-3M-1sec-1 1 x 10-3M-2sec-1 Question 09: In experiment 3, what would be the rate of change of concentration of B measured in M sec-1? Increase at 8 x 10-3 Increase at 2 x 10-3 Decrease at 8 x 10-3 Decrease at 2 x 10-3 Question 10: If Z is an intermediate, which of the following is a possible slow step in the mechanism? 2B → Z B → Z Z → 2B B → Z Δ
