The enthalpy change for the dissolution of one mole of ammonium nitrate (NH₄NO₃) in water is +25.7 kJ/mol. This means the process is endothermic, requiring energy from the surroundings to occur.

Here's why:

* Endothermic Dissolution: When ammonium nitrate dissolves in water, it absorbs heat from the surroundings, causing the solution to become colder. This indicates that the enthalpy change (ΔH) is positive, meaning the process absorbs energy.

* Ionic Compounds: Ammonium nitrate is an ionic compound that dissociates into ammonium ions (NH₄⁺) and nitrate ions (NO₃⁻) when dissolved in water. This process breaks the ionic bonds in the solid and forms new interactions with water molecules.

* Energy Balance: The energy required to break the ionic bonds in the solid is less than the energy released when new interactions form with water molecules. This difference in energy is the enthalpy change of dissolution.

Note: The enthalpy change of dissolution can vary slightly depending on the concentration of the solution and the temperature. However, the value of +25.7 kJ/mol is a good approximation for the standard enthalpy change of dissolution at room temperature.