K + H2S = K2S + H2 K2S + H2S = 2KHS KHS + KOH = K2S + H2O K2S + CuCl2 = CuS + 2KCl CuS + O2= CuO + SO2 ZnO + SO2 = ZnSO3 ZnSO3= ZnO + SO2 прокаливание