Final answer:
The net ionic equation for the reaction between sodium sulfite and excess hydrobromic acid is SO3^2-(aq) + 2H+(aq) → SO2(g) + H2O(l).
Step-by-step explanation:
To write a net ionic equation for the reaction that occurs when sodium sulfite (Na2SO3) and excess hydrobromic acid (HBr) are combined, we start by writing the balanced molecular equation. Sodium sulfite reacts with hydrobromic acid to produce sodium bromide, sulfur dioxide, and water.
The balanced molecular equation is:
Na2SO3(aq) + 2HBr(aq) → 2NaBr(aq) + SO2(g) + H2O(l)
Next, we write the complete ionic equation by breaking all soluble compounds into their respective ions:
2Na+(aq) + SO32-(aq) + 2H+(aq) + 2Br-(aq) → 2Na+(aq) + 2Br-(aq) + SO2(g) + H2O(l)
Finally, we cancel out the spectator ions to get the net ionic equation:
SO32-(aq) + 2H+(aq) → SO2(g) + H2O(l)
This net ionic equation shows the reaction of sulfite ions with hydrogen ions to form sulfur dioxide gas and water.