Write a net ionic equation for the reaction that occurs when excess hydroiodic acid and chromium (II) carbonate (s) are combined.

Include states and charges.

Net ionic equation: 2I⁻ (aq) + Cr²⁺ (aq) → CrI₂ (s)

Explanation: A chemical equation shows chemical symbols of compounds known as reactants and compounds known as products in a chemical reaction. The chemical equation between hydroiodic acid and chromium (II) carbonate is given by;

2HI (aq) + CrCO₃ (aq) → H₂CO₃ (aq) + CrI₂ (s)

The Ionic equation is an equation that shows all the ions involved in a chemical reaction. In this case, the ionic equation is;

2H⁺ I⁻ (aq) + Cr²⁺ CO₃²⁻ (aq) → 2H⁺ CO₃²⁻ (aq) + CrI₂ (s)

The net ionic equation is an equation showing only the ions that take part in the reactions. The ions that do not take part in the chemical reaction known as spectator ions are not shown when writing net ionic equations. Spectator ions are those ions that do not change state after the chemical reaction has taken place. In this case, hydrogen ions and carbonate ions are spectator ions. The net ionic equation is

2I⁻ (aq) + Cr²⁺ (aq) → CrI₂ (s)