Question

balance the following reactions and write their type-
1-NaOH+H2SO4=Na2SO4+H2O
2-HNO3+Ca(OH)2=Ca(NO3)2+H2O
3-FeCl2+H2S=HCl+FeS
4-Fe+O2=Fe2O3

Answer 1

1) NaOH + H2SO4 → Na2SO4 + H2O
balanced :-
2NaOH + H2SO4 → Na2SO4 + 2H2O( displacement reaction )

2) HNO3 + Ca(OH)2 → Ca(NO3)2 + H2O
balanced:-
2HNO3 + Ca(OH)2 →Ca(NO3)2 + 2H2O ( displacement reaction )


(3)FeCl2 + H2S →HCl + FeS
balanced: -
FeCl2 + H2S →2HCl + FeS (displacement reaction )

(4) Fe + O2 → Fe2O3
balanced: -
4Fe + 3O2 → 2Fe2O3
( addition, or oxidation reaction becoz Fe oxidized by adding of oxygen )