Question

Write a net ionic equation for the reaction that occurs when sodium sulfite (aq) and excess hydrobromic acid (aq) are combined

Answer 1

The balanced molecular equation for sodium sulfite(aq) and hydrobromic acid(aq) is,

Na₂SO₃(aq) + 2HBr(aq) H₂SO₃(aq) + 2NaBr(aq)

H₂SO₃ is an unstable product thus,

Na₂SO₃(aq) + 2HBr(aq) H₂O(l) + SO₂(g) + 2NaBr(aq)

Now, the complete ionic equation is,

2Na⁺(aq) + SO₃^2-(aq) + 2H⁺(aq) + 2Br^-(aq) H₂O(l) + SO₂(g) + 2Na⁺(aq) + 2Br^-(aq)

Cancelling the spectator ions,

SO₃^2-(aq) + 2H⁺(aq)   H₂O(l) + SO₂(g) -----------Net ionic equation