Question

Which equation is balanced?

Mg3N2 + H2O 3MgO + 2NH3
C3H8 + 5O2 H2O + 3CO2
Zn + 2HCl ZnCl2 + H2
3H2SO4 + 2Fe Fe2(SO4)3 + H2

Answer 1

Only the third equation is balanced:

1) Mg3N2 + H2O → 3MgO + 2NH3
- Left: Mg 3, N 2, H 2, O 1
- Right: Mg 3, N 2, H 6, O 3 (not balanced)

2) C3H8 + 5O2 → H2O + 3CO2
- Left: C 3, H 8, O 10
- Right: C 3, H 2, O 7 (not balanced)

3) Zn + 2HCl → ZnCl2 + H2
- Left: Zn 1, H 2, Cl 2
- Right: Zn 1, H 2, Cl 2 (balanced)

4) 3H2SO4 + 2Fe → Fe2(SO4)3 + H2
- Left: H 6, S 3, O 12, Fe 2
- Right: H 2, S 3, O 12, Fe 2 (not balanced)