Organic Tests

There are several important tests for organic functional groups. As with all the tests for other types of compounds and groups there are plenty of alternatives and a simple and clear indication that gives reliable results for a specific group is important

Some of these tests are slightly more complex and so there are pages for some of the lengthier tests.

Functional groups tests

Alkenes

Add bromine water (orange in colour)

If a C=C double bond is present the liquid will turn colourless.

Carbonyl compounds

Add 2,4-Dinitrophenylhydrazine

The yellow/orange solution forms a bright yellow / orange / red precipitate which when filtered off can be tested using melting point to determine an exact structure

Aldehydes

See the Tollens’ test page

Carboxylic acids

Although fairly weak acids, carboxylic acids can be detected using typical tests for acids.