The balanced equation for the reaction between hydroiodic acid (HI) and calcium hydroxide (Ca(OH)₂) is:

2 HI (aq) + Ca(OH)₂ (aq) → CaI₂ (aq) + 2 H₂O (l)

Here's a breakdown of the reaction:

* Reactants:

* Hydroiodic acid (HI): A strong acid.

* Calcium hydroxide (Ca(OH)₂): A strong base.

* Products:

* Calcium iodide (CaI₂): A soluble ionic salt.

* Water (H₂O): Formed as a result of the neutralization reaction.

Explanation:

This is a classic acid-base neutralization reaction. The hydrogen ions (H⁺) from the acid react with the hydroxide ions (OH⁻) from the base to form water (H₂O). The remaining ions (Ca²⁺ and I⁻) combine to form the soluble salt calcium iodide (CaI₂).

The coefficients in the balanced equation ensure that the number of atoms of each element on the reactant side is equal to the number of atoms of that element on the product side.