Question

Mg--->H2--->H2O--->H2--->Ag

Answer 1

Mg--->H2--->H2O--->H2--->Ag
1)Mg+H2O=MgO+H2
2)2H2+O2=2H2O
3)2H2O+Ca=Ca(OН)2+H2
4) H2+2AgСl=2HCl+2Ag

Answer 2

Mg+ 2HCl = H2 = MgCl2
2H2 + O2 = 2H2O
H2O + Na= H2 + 2NaOH
H2 + 2AgCl= 2Ag + 2HCl