Answer:
The ion-electron method involves breaking the reactants into their component ions and transferring electrons between the ions to balance the charge and the atoms. In a basic solution, the S²⁰⁸² ion will gain two electrons to form SO₂. The I¹⁻ ion will lose one electron to form I³⁻. The balanced redox equation using the ion-electron method is:
S²⁰⁸² + 2e⁻ + 2OH⁻ → SO₂ + H₂O
I¹⁻ + e⁻ → I³⁻
The overall balanced equation is:
2S²⁰⁸² + 2OH⁻ + I¹⁻ → 2I³⁻ + SO₂ + H₂O