Question

Modified form of rault's law

Answer 1

The form of Raoult's law is modified to express the activity of water [a(H2O)] for aqueous electrolyte solutions by the mole fraction of a free (nonsolvating) solvent structural unit raised to the reciprocal power of the solvent structural constant. Relatively close agreement with experiment, is obtained for a(H2O) of aqueous sodium chloride solutions up to 300°C and nearly saturated concentrations, and of other aqueous electrolyte solutions at 25°C. In an example for aqueous-organic systems, a(H2O) for urea solutions at 25°C is described with an average deviation of 0.09% for molalities from 0 to 20m (54.6 wt%) by using the necessary (universal) structural constant and a single solvation parameter.

Answer 2

P°-P/P=no. of moles of solute/ no. of moles of solvent. this id the modified form of raoult's law this formula is used for dilute and moderately concentrated solutions