Understanding Enthalpy Change of Dissolution
* Endothermic Dissolution: When heat is absorbed from the surroundings during the dissolving process (enthalpy change is positive, ΔH > 0), the solubility of the solute increases with temperature. This is because the system is trying to absorb more heat to compensate for the endothermic process.
* Exothermic Dissolution: When heat is released to the surroundings during the dissolving process (enthalpy change is negative, ΔH < 0), the solubility of the solute decreases with temperature. This is because the system is already releasing heat, so raising the temperature further would disrupt the equilibrium.
Applying it to KHT
Since the solubility of KHT increases with temperature, we can conclude that the dissolution of KHT is endothermic.
Why?
The increased solubility at higher temperatures indicates that the system is absorbing heat to favor the dissolution process. This means the enthalpy change (ΔH) for the dissolution of KHT is positive.
In Summary:
The fact that the solubility of KHT increases with temperature indicates that the enthalpy change of dissolution (ΔH) for KHT is positive. This means the dissolution process is endothermic, absorbing heat from the surroundings.
