Question

Describe the process of each step in the experiment (Fischer esterification/ Isopentyl acetate lab).

a. The reaction is done using a reflux condenser.

b. The reaction mixture is washed with water.

c. The reaction mixture is washed with aqueous sodium bicarbonate.

d. Anhydrous sodium sulfate is added to the top layer.

e. The final product is purified by distillation.

Answer 1

a. In any reaction, if reaction conditions require heating conditions (reflux) the reaction mixture having solvent is set to heat up to the boiling point of the solvent at which it starts refluxing. To make the solvent condense and cool one has to use reflux condenser.

b. Usually, esterification reactions are catalyzed by inorganic acids. To remove the acid from the reaction one has to give the water wash to the reaction mixture.

c. The reaction mixture has to be washed with aqueous sodium bicarbonate to remove any trace amount of the acid present in the reaction mixture after the water wash.

d. Anhydrous sodium sulfate has to be added to the top layer (which is the organic layer) (here top layer means the layer which is top in the separating funnel) to remove the trace amount of water present in the top organic layer.

Sodium sulfate reacts with water and traps it as pentahydrate salt.

e. The final product has to be purified by distillation if any unreacted starting materials left out in the reaction mixture provided they must have significant difference in the boiling points.