Final answer:
The reducing agent in the reaction between zinc metal and hydrochloric acid is zinc metal.
Step-by-step explanation:
The reducing agent in the reaction between zinc metal and hydrochloric acid is zinc metal.
In this reaction, zinc is oxidized and loses electrons to form zinc ions (Zn²+). The hydrogen ions (H+) in the hydrochloric acid are reduced and gain electrons to form hydrogen gas (H₂). Therefore, the zinc metal is the reducing agent because it causes the reduction of the hydrogen ions.