Balance the following equations :
(a) N2+H2→NH3
(b) H2+O2→H2O
(c) Na2O+H2O→NaOH
(d) CO+O2→CO2
(e) Zn+HCI→ZnCl2+H2
1) Zn + 2HCl ----> Zn Cl2 + H2