Question

You and your lab partner are studying the rate of a reaction, A + B --> C. You make measurements of the initial rate under the following conditions:

Experiment	[A] (M)	[B] (M)	Rate (M/s)
1	1.4	1.2
2	2.8	1.2

(a) Which of the following reactant concentrations could you use for experiment 3 in order to determine the rate law, assuming that the rate law is of the form, Rate = k [A]^x [B]^y? Choose all correct possibilities.

[A] = 7.0 and [B] = 1.2[A] = 4.2 and [B] = 1.2[A] = 2.8 and [B] = 3.6[A] = 5.6 and [B] = 1.2[A] = 1.4 and [B] = 2.4[A] = 1.4 and [B] = 3.6[A] = 2.8 and [B] = 2.4[A] = 2.8 and [B] = 1.2

(b) For a reaction of the form, A + B + C --> Products, the following observations are made: tripling the concentration of A increases the rate by a factor of 3, doubling the concentration of B has no effect on the rate, and doubling the concentration of C increases the rate by a factor of 4. Select the correct rate law for this reaction from the choices below.

Rate = k[A][B][C]Rate = k[A][C]     Rate = k[A]² [C]Rate = k[A][C]²Rate = k[A]² [C]²Rate = k[A]³ [C]Rate = k[A][C]³
(c) By what factor will the rate of the reaction described in part (b) above change if the concentrations of A, B, and C are all halved (reduced by a factor of 2)?

The rate will be the original rate multiplied by a factor of  .

Answer 1