Question

Solve for the rate of the iodination of [acetone]= 0.100 M, [H+]= 0.050 M, and [I2]= 0.075 M.

Answer 1

Acid-catalyzed reaction between iodine and acetone in aqueous solution:

CH₃COCH₃ + I₂ ------> CH₃COCH₂I + HI

The rate of this reaction is expected to depend on the concentrations of the reactants.

Rate = k[CH₃COCH₃]^m [I₂]ⁿ[H⁺]^o

Where m, n and o are the orders of the reaction with respect to acetone, iodine and acid respectively and k is the rate constant for the reaction.

Important characteristic of this reaction is that it turns out to be zero-order in I₂ concentration.

Actually the rate of the reaction does not depend on [I₂] .Since the rate of reaction does not depend on [I₂], we can study the rate by simply making I₂ the limiting reagent present in a large excess of acetone. The orders of the reaction with respect to acetone is 1, with respect to iodine is zero and with respect to

H⁺ is 1.

Given: [acetone]= 0.100 M, [H+]= 0.050 M, and [I2]= 0.075 M.

Rate = k[CH₃COCH₃]^m [I₂]ⁿ[H⁺]^o

Rate = k[CH₃COCH₃]¹ [I₂]⁰[H⁺]¹

Rate = k [0.100 M]¹[ 0.075 M]⁰[ 0.050 M]¹