Rate Laws (Section)Consider the reaction of

Chapter 6, Problem 38E

(choose chapter or problem)

Consider the reaction of peroxydisulfate ion \(\left(\mathrm{S}_{2} \mathrm{O}_{8}{ }^{2-}\right)\) with iodide ion \(\left(\mathrm{I}^{-}\right)\) in aqueous solution:

\(\mathrm{S}_{2} \mathrm{O}_{8}{ }^{2-}(a q)+3 \mathrm{I}^{-}(a q) \longrightarrow 2 \mathrm{SO}_{4}{ }^{2-}(a q)+\mathrm{I}_{3}{ }^{-}(a q)\)

At a particular temperature the initial rate of disappearance of \(\mathrm{S}_{2} \mathrm{O}_{8}{ }^{2-}\) varies with reactant concentrations in the following manner:

(a) Determine the rate law for the reaction and state the units of the rate constant. (b) What is the average value of the rate constant for the disappearance of \(\mathrm{S}_{2} \mathrm{O}_{8}{ }^{2-}\) based on the four sets of data? (c) How is the rate of disappearance of \(\mathrm{S}_{2} \mathrm{O}_{8}{ }^{2-}\) related to the rate of disappearance of \(\mathrm{I}^{-}\)? (d) What is the rate of disappearance of \(\mathrm{I}^{-}\) when \(\left[\mathrm{S}_{2} \mathrm{O}_{8}{ }^{2-}\right]=0.025 \mathrm{M}\) and \(\left[\mathrm{I}^{-}\right]=0.050 \mathrm{M}\)?