Question

Ileat of solution is defined as (1) Heat required in dissolving 1 mole in excess of water. (2) Heat evolved when 1 mole is dissolved in excess of water. (3) Change in heat content of the system when I mole of the solute is dissolved in excess of water so that further dilution of solution does not bring any heat change. (4) None of the above.

Short answer

Option (3) is correct.

Step-by-step solution

Identify the Term

The term in question is 'Heat of solution'.

Understand the Definitions

Review the definitions given for heat of solution:1. Heat required in dissolving 1 mole in excess of water.2. Heat evolved when 1 mole is dissolved in excess of water.3. Change in heat content of the system when 1 mole of the solute is dissolved in excess of water so that further dilution of the solution does not bring any heat change.4. None of the above.

Analyze the Correct Definition

Heat of solution is generally defined as the change in heat content when 1 mole of a solute is dissolved in a large amount of solvent (typically water), such that further dilution does not change the heat content.

Correct Definition Statement

Match the correct definition with the given options. The third definition matches our understanding.

Key concepts

enthalpy change

When discussing the heat of solution, it's crucial to understand the concept of enthalpy change. Enthalpy change, denoted as \( \Delta H \), represents the heat absorbed or released during a chemical reaction at constant pressure. In the context of a solution, it refers to the energy change when a solute dissolves in a solvent.
The overall enthalpy change (\