Question

Oh no... not again... Prof. Vitarelli spots Sybil running down the hall... yelling something... something about her tea cups... Prof. Vitarelli and Prof. Snape try to hold her back. But they fail. She yells, I’ve learned another exam question from last year! Zinc metal reacts with hydrochloric acid to produce hydrogen gas and an aqueous solution of zinc(II) chloride. What is the reducing agent in this reaction? Maybe Prof. Umbridge was right in trying to remove her.

Answer 1

Answer:

The reducing agent is Zn.

Explanation:

Let's consider the reaction between zinc and hydrochloric acid.

Zn(s) + 2 HCl(aq) ⇄ ZnCl₂(aq) + H₂(g)

This is a redox reaction, which can be divided in 2 half-reactions: reduction and oxidation.

In the reduction, H⁺ gains electrons and it is considered the oxidizing agent.

2H⁺ + 2 e⁻ ⇒ H₂

In the oxidation, Zn loses electrons and it is considered the reducing agent.

Zn ⇒ Zn²⁺ + 2 e⁻