4.(1) At atmospheric pressure, ethyl acetate and ethyl alcohol form an azeotrope containing 53.9%(mol) acetate boiling at 345K. Determine: (a) The van Laar constants (b) The azeotropic composition and the total pressure if the mixture forms an azeotrope boiling at 329.5K (c) The composition of the vapour in equilibrium with a liquid of composition 60%(mol) alcohol and boiling at 329.5K (2) For the acetone (1)-diethylamine (2) system the activity coefficients values as function of concentration are given below: Using the above data estimate the van Laar constants for the system