balance these equations :
a. H2 + 02 H20
b. S8+ 02 S03
c. HgO Hg+ 02
d. Zn+ HCl ZnCl2+ H2
e. Na+ H20 NaOH + H2 f. C10H16+ CI2 C+ HCl
g. Fe+ 02 Fe203
h. C6H1206+ 02 C02+ H20 i. Fe203 + H2  Fe + H20
j. Al+ FeOAl2O3 + Fe