Question

You are presented with the following compound: 2-propanol. Describe below the series of experiments that would be necessary to perform (and what observations you would expect) to conclusively verify qualitatively that it contains an alcohol.

Answer 1

(1) Add sodium metal to the solution of the compound in a suitable solvent (such as dry ether or benzene).

The bubbles of hydrogen gas will confirm the presence of -OH group.

(2) When phosphorous pentachloride is added to solution of the compound, the mixture becomes warm with liberation of HCl gas. This will confirm the presence of -OH group.

(3) When acetyl chloride or benzoyl chloride is added to the compound, the liberation of HCl gas with separation of an oily layer will confirm the presence of -OH group. If the compound was taken in an organic solvent the oil ester may dissolve in it and the liberation of HCl has indicates the presence of -OH group.