The mole ratio of H2SO4 and H2O in the equation = 3:3
Given
Reaction
Fe2O3 + H2SO4 → Fe2(SO4)3 + H2O
Required
Balanced equation
Solution
Fe₂O₃ + H₂SO₄ → Fe₂(SO₄)₃ + H₂O
aFe₂O₃ + bH₂SO₄ → Fe₂(SO₄)₃ + cH₂O
Fe, left = 2a, right=2⇒2a=2⇒a=1
S, left=b, right=3⇒b=3
H, left = 2b, right = 2c⇒2b=2c⇒2.3=2c⇒c=3
The equation becomes :
Fe₂O₃ + 3H₂SO₄ → Fe₂(SO₄)₃ + 3H₂O