Consider the following proposed mechanism for the decomposition of hydrogen peroxide in aqueous solution:
Step 1: I−(aq)+H2O2(aq)→IO−(aq)+H2O(l)
Step 2: IO−(aq)+H2O2(aq)→I−(aq)+H2O(l)+O2(g)
Which species acts as a catalyst in this mechanism?
a) IO−
b) H2O
c) I−
d) H2O2