Which purification technique is used for high boiling organic liquid compound (decomposes near its boiling point)?
- (A)Fractional distillation
- (B)Steam distillation
- (C)Simple distillation
- (D)Reduced pressure distillation✓ Correct
Answer: (D)
Solution
A liquid that decomposes at or near its normal boiling point cannot be purified at atmospheric pressure, because it breaks up before it distils. Lowering the pressure above the liquid lowers the temperature at which its vapour pressure equals the external pressure, so it boils well below its decomposition temperature. Steam distillation applies to compounds that are volatile in steam and immiscible with water, while simple and fractional distillation both operate at atmospheric pressure. The technique used is distillation under reduced pressure.
JEE Main · 2021 · 22 Jul 2021 · Shift 2 · Single correct option