Primary alcohols and aldehydes are normally oxidized to carboxylic acids using potassium dichromate(VI) solution in the presence of dilute sulphuric acid. During the reaction, the potassium dichromate(VI) solution turns from orange to green. Primary alcohols are oxidized to carboxylic acids in two stages – first to an aldehyde and then to the acid. The aldehyde is then oxidized further to give the carboxylic acid.
