7.1 (Equilibrium in a binary mixture) 1 Mixtures of n-hexane and n-octane form essentially ideal solutions. (a) Prepare the bubble point, dew point and equilibrium curves (Txy and xy plots) at 1 atm total pressure. (b) Calculate the values of the relative volatility of n-hexane and n-octane in mixtures containing 10 mole % and 90 mole % hexane using vapour pressure equations given in Table 7.2. Do these values suggest that the solutions may be ideal? (c) A solution of concentration x=0.2 is slowly heated. What is the composition of the initial vapour formed if the total pressure is (i) 1atm, (ii) 2atm ? (d) If a vapour of composition as in part (c) (ii) above is cooled at 2 atm total pressure and a differential amount of vapour is formed from the condensate, calculate its composition. How can the quantities be calculated using the Txy and xy data