2 HIICl2 + 2 Zn0 2 ZnIICl2 + H20

This is an oxidation-reduction (redox) reaction:

2 Zn0 - 4 e- 2 ZnII (oxidation)

2 HII + 4 e- 2 H0 (reduction)

Zn is a reducing agent, HCl2 is an oxidizing agent.