RP6-Organic tests

• Test for an alcohol - a metal: Add a small piece of sodium to the alcohol. Hydrogen gas is produced, which can be tested for by the squeaky pop test.
• Test to determine between alcohols - potassium dichromate: When acidified potassium dichromate is added to the solution, primary and secondary alcohols will reduce it from orange dichromate (vi) ions to green chromium (iii) ions, while tertiary alcohols have no effect.
• Test for an aldehyde - Fehling's solution: Warm gently with the aldehyde for a couple of minutes. Leave to stand, and a brick red precipitate should form (originally a dark blue solution).
• Test for an aldehyde - Tollens' reagent: Add a few drops. After a few minutes, a silver mirror should form as a positive result.
• Test for an alkene -bromine water: Shake with the alkene. Bromine water will turn orange to colourless if an alkene is present.
• Test for a carboxylic acid - sodium carbonate: Collect the gas produced when a carboxylic acid is reacted with sodium carbonate. Bubble through limewater (calcium hydroxide), and it will turn cloudy.
• Test for a halogenoalkane - sodium hydroxide and silver nitrate: Warm a mixture of sodium hydroxide and the halogenoalkane at about 60 degrees. Then add nitric acid to acidify the mixture and remove impurities and add silver nitrate solution. A silver - halogen precipitate forms (yellow, cream or white).