$1.$

UNIT$-$I

$($a$)$ What is the difference between steam and flash distillation?

$(5)$

$($b$)$ A continuous distillation column is to be designed $7000$ kg$/$hr of liquid mixture with $60\%$ methanol and $40$ mole $\%$ water into an overhead product containing $90$ mole $\%$ methanol and water product $95$ mole $\%$ water. Reflux ratio of $2$ times the minimum value is used. Assume relative volatility of methanol and water is $3.$ Calculate $($i$)$ the moles of overhead of water product. $($ii$)$ Number of ideal trays and feed tray if the feed is at boiling point. $(10)$

$2.$

$($a$)$ Explain, how azeotropic mixtures are separated?

$(5)$

$($b$)$ In a binary mixture the vapor pressure of A is $800$ mm Hg and that of B is $400$ mm Hg$.$ Estimate the vapor composition in equilibrium with the liquid if the composition in liquid phase is $50$ mole $\%$ A$.$