Respuesta :

In the reaction Sn(s) + 2H+(aq) → Sn2+ (aq) + H2(g)
from this reaction, we get that Sn loses from 0 to 2 electrons so it's oxidized So it is the reducing agent.
and H  gains from 0 to 1 electrons so, it's reduced so ∴ it is the oxidizing agent

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, [tex]2H^{+} + 2e^{-} \rightarrow H_{2}[/tex]

Here, hydrogen 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.

Whereas in [tex]Sn \rightarrow Sn^{2+} + 2e^{-}[/tex], tin is getting oxidized by gaining electrons. Therefore, it is acting as a reducing agent. An increase in oxidation state occurs for a reducing agent.

Thus, we can conclude that in the given reaction hydrogen is the oxidizing agent.