what is the enthalpy if dilution

Enthalpy of dilution (often called heat of dilution) is the change in enthalpy when a solution is diluted at constant pressure, i.e., when you add more solvent to a solution and its concentration decreases.

Quick meaning

• It measures how much heat is absorbed or released when a solution is made more dilute.

• It is usually expressed per mole of solute, in kJ/mol or J/mol.

• If the process releases heat (solution warms up), enthalpy of dilution is negative (exothermic). If it absorbs heat (solution cools), it is positive (endothermic).

A simple way to picture it: imagine concentrated HCl being diluted with water. As you add water, ion–solvent interactions change and heat is usually released; the enthalpy of dilution tells you how much heat is involved per mole as you go from the initial to the more dilute concentration.

Integral vs. differential (briefly)

• Integral enthalpy of dilution : total enthalpy change when you dilute a solution from one definite concentration to another, divided by moles of solute.

• Differential enthalpy of dilution : enthalpy change when you add a very small amount of solvent to a large amount of solution, so the concentration changes only infinitesimally.

In practice, tables or graphs of enthalpy of dilution for electrolytes (like HCl or H₂SO₄) are used in thermodynamics and solution chemistry to predict temperature changes during mixing and to design processes safely.

Information gathered from public forums or data available on the internet and portrayed here.