Heats of solution of NaBPh(4), and Ph(4)PCl in the mixtures of ethanediol-1,2, propanediol-1,2 and butanediol-1,2 with water in almost the whole composition range were measured at 25 degrees C. Plots of the determined standard enthalpies of solution, Delta(sol)H(o), vs. diols content in mixed solvents were examined. Close positions of Delta(sol)H(o) maxima to the apparent molar volume minima, V-phi are discussed for solutions of the salts in water with diols as well as in water with alcohols. The linear correlation of Delta(tr)H(o),, maxima positions vs. the number of equivalent CH2 groups included in diol and alcohol molecules was found.