Розтавити коефіцієнти PbS+ O2- PbO+SO2 Cu+O2-CuO N2+H2- NH2 Zn+HCl- ZnCl+H2
2PbS+3O2=2PbO+2SO2 2Cu+O2=2CuO N2+2H2=2NH2 2Zn+2HCl=2ZnCl+H2