JEE Main · 2016 · 03 Apr 2016 · Offline · Practical and Analytical Chemistry

The distillation technique most suited for separating glycerol from spent-lye in the soap industry is :

(A)Fractional distillation
(B)Steam distillation
(C)Distillation under reduced pressure✓ Correct
(D)Simple distillation

Answer: (C)

Solution

Glycerol boils near

290^{\circ}

C at ordinary pressure and starts to decompose before it gets there, so it cannot be distilled straight. Lowering the pressure lowers its boiling point enough for it to distil over intact, which is why distillation under reduced pressure is the technique used to separate glycerol from spent-lye.

JEE Main · 2016 · 03 Apr 2016 · Offline · Single correct option

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