Cu2As2O7 + 10 Zn + 10 H2SO4 → 2 Cu + 2 AsH3 + 10 ZnSO4 + 7 H2O
This is an oxidation-reduction (redox) reaction:
2 CuII + 4 e- → 2 Cu0 (reduction)
2 AsV + 16 e- → 2 As-III (reduction)
10 Zn0 - 20 e- → 10 ZnII (oxidation)
Cu2As2O7 is an oxidizing agent, Cu2As2O7 is an oxidizing agent, Zn is a reducing agent.