Which option shows a correctly balanced chemical equation?

H₂O ⟶ H₂ + O₂
2Fe₂O₃ + C ⟶ Fe + 3CO₂
FeS + 2HCl ⟶ FeCl₂ + H₂S
2Na₃PO₄ + 3MgCl₂ ⟶ 6NaCl + Mg₃PO₄

1 answer

To determine which option shows a correctly balanced chemical equation, we need to check each equation for balance. A balanced equation has the same number of each type of atom on both sides of the equation.

  1. H₂O ⟶ H₂ + O₂
    Left side: 2 H, 1 O
    Right side: 2 H, 2 O
    This equation is not balanced.

  2. 2Fe₂O₃ + C ⟶ Fe + 3CO₂
    Left side: 4 Fe, 6 O, 1 C
    Right side: 1 Fe, 6 O, 3 C
    This equation is not balanced.

  3. FeS + 2HCl ⟶ FeCl₂ + H₂S
    Left side: 1 Fe, 1 S, 2 Cl, 2 H
    Right side: 1 Fe, 2 Cl, 1 S, 2 H
    This equation is balanced.

  4. 2Na₃PO₄ + 3MgCl₂ ⟶ 6NaCl + Mg₃PO₄
    Left side: 6 Na, 2 P, 8 O, 6 Cl, 3 Mg
    Right side: 6 Na, 1 P, 4 O, 6 Cl, 3 Mg
    This equation is not balanced.

The only correctly balanced equation from the options provided is:
FeS + 2HCl ⟶ FeCl₂ + H₂S.