Testing for functional groups


Test for alkenes

Add bromine water:

If alkenes are present it should turn from red/brown to colourless

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Testing for haloalkanes


Warm with NaOH (Aq) the accidify and add AgNO3 


If there is a haloalkane present a precipitate will form;

White precipitate indicates chlorine 

Cream precipitate indicates bromine

Yellow precipitate indicates iodine

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Testing for alcohol


Warm with acidified pottassium dichromate (VI)


Colour change from green to orange

This will not happen for tertiary alcohols

This will alos happen with aldehydes

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Testing for Aldehydes

Fehlings solution: (Warm)

From blue solution to red precipitate if aldehyde is present

Tollens' reagent: (Warm in water bath)

Silver mirror should form on inside of test tube if it is present 

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Testing for phenol

Add iron (III) chloride

A purple colour should form 

- Will also from for any other phenolic OH

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Testing for Carboxylic Acids

Add sodium carbonate solution

If carboxylic acids are present then bubbles of gas should form

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