Test for functional groups

To be able to distinguish between chemicals

> Oxidize alcohols using acidified potassium dichromate Add 10 drops of the alcohol to 2cm3 of the chromate Warm the mixture in a water bath Primary and secondary alcohols will turn from orange to green while tertiary alcohols will remain orange/no reaction

> Sodium metal Add a small piece of sodium to a pure alcohol and it will fizz as it gives off hydrogen gas

Because its being reduced

> Fractional distillation setup Distill an alcohol, if an primary alcohol, it will produce an aldehyde which will turn brick red in Fehling’s and benedicts solution Distill an alcohol, if an secondary alcohol, it will produce an Ketone, there will be no reaction in Fehling’s and benedicts solution Or reflux both alcohols, if a primary alcohol, a carboxylic acid is formed which fizz, or form an effervescence in sodium carbonate

> Add sodium carbonate to 2cm3 of carboxylic acid which will fizz and produce co2. Bubble through limewater to turn cloudy

> Tollens reagent, forms a silvery mirror Fehling’s solution, turns from deep blue to brick red precipitate

> Tollens reagent, no reaction Fehling’s solution, no reaction

> Heat with aqueous sodium hydroxide Then acidify with nitric acid then add silver nitrate solution For chloride, a white precipitate is formed For bromide, a cream precipitate is formed For iodide a yellow precipitate is formed

> Add 2cm3 of alkene and 2cm3 of bromine water and shake gently Orange bromine water decolourises