* Solvent: The substance that dissolves the other substance, usually present in a larger amount.

* Solute: The substance that gets dissolved.

In this case:

* KCl (potassium chloride) is the solute, as it's dissolving in the water.

* Water (H₂O) is the solvent, as it's the substance in which the KCl is dissolving, and it's present in a much larger amount (100 grams) than the KCl (5 grams).