Chapter 13.1, Problem 13.2E

Iodide ion is oxidized by hypochlorite ion in basic solution.

${\text{I}}^{-}(aq)+{\text{ClO}}^{-}(aq)\stackrel{}{\to }{\text{Cl}}^{-}(aq)+{\text{IO}}^{-}(aq)$

In 1.00 M NaOH at 25°C, the iodide-ion concentration (equal to the ClO⁻ concentration) at different times was as follows:

Time	[I− ]
2.00 s	0.00169 M
8.00 s	0.00101 M

Calculate the average rate of reaction of I⁻ during this time interval.