1) Ca + 2HCl = CaCl2 + H2;
2) 2Au + 2HBr = 2AuBr + H2
3) 6Na + 2H3PO4 = 2Na3PO4 + 3H2;
4) 2Ag + 2HCl = 2AgCl +H2;
5) Zn +2HI= ZnI2 + H2;
6) 2Na + 2HI = 2NaI + H2;
7) 2Al + 6HI = 2AlI3 = 2AlI3 + 3H2;
8) Hg + 2HCl = HgCl2 + H2;
9) 2Cu + HBr = 2CuBr + H2.