H2S → X → K2SO3 → CaSO3+O2ZnS → Х → ZnCl2 → Zn (OH) 2

1) 2H2S+3O2=2H2SO3 H2SO3+2KCl=K2SO3+2HCl K2SO3+CaCl2=CaSO3+2KCl 2) 2ZnS+3O2=2ZnO+2SO2 ZnO+2HCl=ZnCl2+H2O ZnCl2+2NaOH=Zn (OH) 2+2NaCl 3) Pb (OH) 2+2HCl=PbCl2+2H2O PbCl2+2HNO3=Pb (NO3) 2+2HCl Pb (NO3) 2+H2=Pb+2HNO3