Correct Answer: 2.5% of H, 39% of S, 58.5% of O

Solution : The correct option is 2.5% H, 39% S, 58.5% O .

Molar mass of H ₂ SO ₃ = (2 x 1 g/mol) + (1 x 32 g/mol) + (3 x 16 g/mol) = 82 g/mol.

• Hydrogen (H): (2*molar mass of H)/(molar mass of H ₂ SO ₃ )*100% = (2 g/mol/82 g/mol)*100% ≈ 2.44%;
• Sulphur (S): (1*molar mass of S)/(molar mass of H ₂ SO ₃ )*100% = (32 g/mol/82 g/mol)*100% ≈ 39.02%;
• Oxygen (O): (3*molar mass of O)/(molar mass of H ₂ SO ₃ )*100% = (3*16 g/mol/82 g/mol)*100% ≈ 58.54%.