Answer: zinc is the reducing agent.
Explanation:
1) Reducing agent is the agent that releases electrons, is oxidized (its oxidation number increases) Â and causes the reduction of the other agent (the reduced spices reduces its oxidation state).
2) Chemical equation:
Zn(s) + HCl (aq) → H2(g) + ZnCl2(s)
3) determine the oxidation states of each spices
Zn (s): oxidation state = 0
Zn in ZnCls: oxidation state = + 2.
Therfore Zn was oxidized and is the reducing agen.
H in HCl: oxidtation state = +1
H in H2: oxidation state = 0
Therefore H2 was reduced (it is the oxidizing agent).