In+HCl= Fe+HSO3= K+H3PO4= In+H3PO4=
2In+6HCl=2InCl3+3H2 Fe+H2SO3=FeSO3+H2 2In+2H3PO4=2InPO4+3H2 6K+2H3PO4=2K3PO4+3H2