11 P + 15 CuSO4 + 24 H2O → 5 Cu3P + 15 H2SO4 + 6 H3PO4
This is an oxidation-reduction (redox) reaction:
5 P0 + 15 e- → 5 P-III (reduction)
6 P0 - 30 e- → 6 PV (oxidation)
15 CuII + 15 e- → 15 CuI (reduction)
P is an oxidizing agent, P is a reducing agent, CuSO4 is an oxidizing agent.