ZnCl2+Ba(OH)2=Zn(OH)2+BaCl2 Zn+2Cl+Ba+2OH=Zn(OH)2+Ba+2Cl Zn+2OH=Zn(OH)2 3K2S+2H3PO4=2K3PO4+3H2S 6K+3S+6H+2PO4=6K+2PO4+3H2S S+2H=H2S