Chapter 11, Problem 31QAP

In a solution at a constant H⁺ concentration, iodide ions react with hydrogen peroxide to produce iodine.

  ${\text{H}}^{+}\left(aq\right)+{\text{I}}^{-}\left(aq\right)+\frac{1}{2}{\text{H}}_2{\text{O}}_2\left(aq\right)\to \frac{1}{2}{\text{I}}_2\left(aq\right)+{\text{H}}_2\text{O}$The reaction rate can be followed by monitoring the appearance of I₂. The following data are obtained:

(a) What is rate expression for the reaction?

(b) Calculate k

(c) What is the rate of the reaction when 25.0 mL of a 0.100 M solution of KI is added to 25.0 mL of a 10.0% by mass solution of ${\text{H}}_2{\text{O}}_2\left(d=1.00\text{g}/\text{mL}\right)$ ? Assume volumes are additive.