${\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{CuSO}}_4\left(\mathrm{aq}\right):\mathrm{\Delta H}$  The corresponding heat change in above reaction is called:

Change in enthalpy when one mole of the solute is dissolved in excess of solvent so that further dilution does not bring any heat change.