Question

Describe how a rotary evaporator removes the solvent and isolates dry product. (Hint: partial pressures, boiling points of the solvents, and the water bath. You can draw a diagram if needed be.)

Answer 1

The rotary evaporator is a sophisticated distillation apparatus. It distills out the solvent, mostly at reduce pressure, so at reduced temperature.

A vacuum is applied during the vaporation which brings down the boilling point of solvent but the product remained as hig boiling liquid or as a solid.

The rotation of the flask is necessary for the mixinng as well as craeting more surface area and preventing the bulk of the liquid from bumping under vacuum.

Water bath is to provide the necessary heat to maintain the temperature because when the solvents are taken out at low pressure or under vacuum, the bulk of the liquid gets cooled down.

So, the main components are, a vacuum pump, a water bath, a rotor with a control panel and the flask.