Qualitative Tests for Alcohols

Contents

• Qualitative tests for alcohols

Learning
Objectives

At the end of this
lecture, student will be able to

• Explain the qualitative tests for alcohols

Qualitative
tests for Alcohols

• Alcohols are compounds in which the hydroxyl group (-OH)
is linked to aliphatic carbon chain or in the side chain of an organic compound

• Further classified as primary (1°), secondary (2°) and
tertiary (3°) according to the –OH group is attached to the primary, secondary
and tertiary carbon atoms respectively

• Sodium metal test

• Alcohols react with active metals like sodium and liberate
hydrogen gas that can be observed in the form of effervescence

Jones
Oxidation for Primary and Secondary Alcohols

• Jones reagent (chromic acid in sulfuric acid)

• Formation of green color within 15 sec- primary or
secondary alcohol

• Tertiary alcohols- remain orange in color

Lucas Test
for Secondary and Tertiary Alcohols

• Lucas reagent- Zinc chloride in HCl

• Formation of alkyl chloride as insoluble layer or emulsion

• 3o alcohols: immediate to 2-3 minutes

• 2o alcohols: 5 -10 minutes

• 1o alcohols: no reaction

Summary

• Jones Oxidation for Primary and Secondary Alcohols

• Lucas Test for Secondary and Tertiary Alcohols