Final answer:
The salt likely to show the greatest change in solubility with increasing temperature per 100 g solvent is KClO4, owing to the steep increase in its solubility curve similar to that of KNO3.
Step-by-step explanation:
For which salt will increasing the temperature of the water have the greatest change in solubility per 100 g solvent? The solubility of solids typically increases with temperature, as seen with substances like KNO3. However, each compound has a distinct solubility curve, and general trends cannot always predict individual solubility behaviors. Specifically, ammonium compounds like NH₄Cl could display a decrease in solubility upon heating due to its ionic nature and potential gas release. However, comparing to a solubility curve for each substance mentioned, typically salts such as KClO₄, which are perchlorates, often have a sharp increase in solubility with temperature, emulating trends like those of KNO3, hence might display the greatest change in solubility.