Balance the equation. Then add up the coefficients on both sides of this properly balanced equation and identify the total.

N2 + H2 → NH3
KNO3 + H2CO3 → K2CO3 + HNO3
Na3PO4 + HCl → NaCl + H3PO4
KClO3 + P4 → P4O10 + KCl
Hg(OH)2 + H3PO4 → Hg3(PO4)2 + H2O
Fe + HC2H3O2 → Fe(C2H3O2)3 + H2