The iodate ion is reduced by sulfite according to the following reaction:

The rate of this reaction is found to be first order in IO3-, first order in SO32-, and first order in H+.
(a) Write the rate law for the reaction.
(b) By what factor will the rate of the reaction change if the pH is lowered from 5.00 to 3.50? Does the reaction proceed more quickly or more slowly at the lower pH?
(c) By using the concepts discussed in Section 14.6, explain how the reaction can be pH-dependent even though H+ does not appear in the overall reaction.