Salt effect on the enthalpy of mixing of water+methanol at 303.15 K

The excess enthalpy of the miscible water–methanol system has been measured at 303.15 K in an isothermal batch calorimeter with vapour space. The effect of the salts NH4Cl, CdCl2 and HgCl2 on HE was studied. A decreasing trend in excess enthalpy for NH4Cl and HgCl2 but an increasing trend for CdCl2 with increasing salt concentrations have been observed. The experimental values of HE have been correlated using a modified Redlich–Kister equation and the binary parameters have been estimated. The deviations were calculated and reported.