Final answer:
The factors determining hydration enthalpy include ionic charge, ionic radius, solvent, and temperature. Ionic charge and radius affect the strength of the interactions between ions and water molecules, while the solvent and temperature influence the ability of water to form a hydration shell around the ions.
Step-by-step explanation:
The factors determining hydration enthalpy include ionic charge, ionic radius, solvent, and temperature.
1) Ionic charge: The magnitude of the charge on an ion affects its hydration enthalpy. Higher charges result in stronger attractions between the ion and water molecules, leading to higher hydration enthalpies.
2) Ionic radius: Smaller ions have a higher hydration enthalpy compared to larger ions. This is because smaller ions can form stronger interactions with water molecules due to their closer proximity.
3) Solvent: The nature of the solvent also influences hydration enthalpy. In general, water has a high dielectric constant and can effectively form hydrogen bonds with ions, resulting in high hydration enthalpies. Other solvents may have different dielectric constants and interactions, leading to different hydration enthalpies.
4) Temperature: Increasing temperature generally decreases the hydration enthalpy. This is because at higher temperatures, water molecules have more kinetic energy and are more likely to break the hydration shell around the ions.