H2SO4 --- SO2 --- S --- ZnS --- ZnO --- ZnCl2
2H2SO4 + Zn = SO2↑ +ZnSO4 + 2H2O
SO2 + 2 H2S = 3 S + 2 H2O
Zn+S=ZnS
2ZnS + 3O2 = 2ZnO + 2SO2
ZnO + 2HCl (разб.) = ZnCl2 + H2O