Chapter 13, Problem 13.25P

Interpretation Introduction

Interpretation:

The enthalpy term in the thermochemical solution cycle that is combined to obtain $\Delta H_{\text{solvation}}$ for a general solvent is to be determined.

Concept introduction:

The enthalpy is the thermodynamic property of the system. It is defined as the sum of internal energy and the product of pressure and volume of the system. It is a state function and is independent of the path followed by the system from initial to the final state. It is an extensive property. The total enthalpy of the system cannot be measured directly so the change in enthalpy $\left(\Delta H\right)$ is measured. If $\Delta H$ of the reaction is positive, it is an endothermic reaction and if $\Delta H$ of the reaction is negative, it is an exothermic reaction.

The interaction between the solute and solvent molecules is called solvation. It is also known as dissolution. It is a method to form solvation complexes from solute and solvent molecules. The enthalpy change of solvation is the enthalpy change when one mole of the ions are dissolved in a solvent to form a solution of infinite dilution. It is represented by $\Delta H_{\text{solvation}}$ and its values are always negative.