Alcohol

Procedure

(a) To 0.2 mL or 0.2 g of the sample in a test tube add 2 mL of the Lucas reagent at 26-27^oC. Stopper the tube and shake; then allow the mixture to stand. Note the time required for the formation of the alkyl chloride, which appears as an insoluble layer or emulsion. Note by means of a watch the time required for the reaction to take place.

Lucas Reagent: Dissolve 13.6 g (0.1 mole) of anhydrous zinc chloride in 10.5 g (0.1 mole) of concentrated hydrochloric acid, with cooling.

Positive Test

Appearance of a cloudy second layer or emulsion.

• 3^o alcohols - immediate to 2 - 3 minutes
• 2^o alcohols - 5 - 10 minutes
• 1^o alcohols - no reaction

Complications

The test applies only to those alcohols soluble in the reagent (monofunctional alcohols lower than hexyl and some polyfunctional alcohols).