Question

While doing a distillation, Farha heats the mixture too fast, and the temperature rises too quickly. If the mixture is composed of two liquids, how will this likely affect the separation of the mixture?
A) The liquids will be separated in reverse order.
B) Both liquids will evaporate and escape into the air.
C) The liquid with the lower density will be collected before the liquid with the higher density.
D) Some liquid with the higher boiling point will be collected along with the liquid with the lower boiling point.

Answer 1

D as the two substances could have close boiling points, so if the temperature is not controlled well, both substances will evaporate.

Answer 2

Answer is: D) Some liquid with the higher boiling point will be collected along with the liquid with the lower boiling point.

For example if we have mixture of water and alcohol ethanol, we can separate water and ethanol with distillation (process of heating and cooling).

Ethanol and water have different boiling points (physical property), ethanol has boiling point (78.37°C) and water (100°C).

When the mixture is quickly heated, water contains a lot of ethanol.

The temperature should stay more or less constant.