Question

Which change requires an oxidising agent?

Answer 1

The increase in oxidation number requires an oxidising agent.

Answer 2

Explanation:

An oxidizing agent is defined as a substance which readily accepts an electron and itself gets reduced in order to oxidize another substance in a chemical reaction.

For example, $Li^{+} + 1e^{-} \rightarrow Li$

Here, lithium is getting reduced as its oxidation state is changing from +1 to 0 and hence it acts like an oxidizing agent.

In an oxidizing agent, a decrease in oxidation state occurs.

Thus, we can conclude that an oxidising agent requires a decrease in oxidation state.