Balance these chemical equations.

(a)	Na2SO4 (s) + C (s) Na2S (s) + CO2(g)
(b)	Ag2SO4 (aq) + BaI2 (aq) BaSO4 (s) + AgI (s)
(c)	HCl (g) + O2 (g) H2O (l) + Cl2 (g)
(d)	CH4 (g) + O2 (g) CO2 (g) + H2O (l)
(e)	Cl2 (g) + P4 (s) PCl3 (l)
(f)	sodium metal reacts with liquid water produces aqueous sodium hydroxide, NaOH, and hydrogen gas.
(g)	Zinc metal dissolves in hydrochloric acid solution, HCl, produces zinc (II) chloride solution and hydrogen gas.
(h)	Write the balanced equation for the combustion of benzene, C6H6.