Question

Which is an intermediate in this reaction mechanism: step 1: H2O2 + I- → H2O + OI- step 2: H2O2 + OI- → H2O + O2 + I- A. H2O2 B. I- C. OI- D. O2

Answer 1

`OI^-`

Step-by-step explanation:

An intermediate is defined as species which are produced in one step of a reaction and consumed in the other. It is important not to confuse an intermediate with a catalyst. Catalyst is consumed in one reaction and produced in one of the subsequent reactions.

Given the mechanism of this reaction, in the first step we produce
`OI^-`. Notice that the same species,
`OI^-`, is produced in the subsequent step 2. In this case,
`OI^-` is the intermediate, as it follows the definition of an intermediate.

For your own information, iodide anion is a catalyst, as it's consumed in step 1 and reproduced in step 2.