Chemistry · THERMODYNAMICS

For most ionic compounds, the enthalpy of solution (\( \Delta_{\text{sol}} H^\ominus \)) is positive, yet they dissolve in water. Why does the solubility of most such salts increase with a rise in temperature?

1. A
   Because hydration enthalpy becomes infinitely negative at elevated temperatures.
2. B
   Because the dissolution is endothermic, and according to Le Chatelier's principle, an increase in temperature shifts the equilibrium towards dissolution.
3. C
   Because lattice enthalpy decreases to zero at higher temperatures.
4. D
   Because ionic radius of cations decreases upon heating, decreasing the hydration shell.