Chapter 12, Problem 4Q

Interpretation Introduction

Interpretation:

The reason for the use of a steam bath as the heat source for the distillation of diethyl ether rather than heating mantle should be determined.

Concept introduction:

Distillation is a liquid-gas separation technique for two or more liquids on the basis of their difference in boiling temperature or vapor pressure.Vapor pressure is pressure exerted by vapor phase of liquid produced due to an increase in the molecular kinetic energy of the liquid phase or due to the increase in temperature.

The temperature at which atmospheric pressure exerted on liquid equals to its vapor pressure is known to be its boiling point. Vapor pressure of the component decide boiling point of any mixture. Impurities in the mixture might result in an increase or decrease of observed boiling temperature.

The steps for distillation are as follows:

• In distillation, a round bottom flask is filled one-third or half full with the liquid compound to be distilled. If the flask is overfilled it might flow inside condenser attached to it.

• Then a distilling head is inserted into the round bottom flask and then a condenser is attached to the side joint of the distilling head from where the compound is collected in another smaller round bottom flask after distillation.

• A heat source is placed below the distillation flask.

• A thermometer is carefully inserted in the thermometer adaptor and is placed properly on the distillation head for measuring the boiling temperature of the compound being distilled.