When 4.7g of a salt with a formula mass of 100g/mol is dissolved in 513g of water 609 cal of heat are evolved. When 10.6g of the salt are dissolved in 493g of water 1143 cal of heat are evolved. Calculate the differential heat of solution of this salt at 1.5 molal. Why does the integral heat of solution at infinite dilution equal the differential heat of solution at zero molality? Why would the slope of a plot of the integral heat of solution versus molality approach zero as the molality approaches zero?