It is often used as a reactive in chemical assays of recognition for substances which react with bromine in an aqueous environment with the halogenation mechanism. The most common compounds that react well with bromine water are phenols, alkenes, enols, the acetyl group, aniline, and glucose. In addition, bromine water is commonly used to test for the presence of an alkene which contains a double covalent bond which reacts with the bromine water which changes its color from an intense yellow to a colorless solution. Bromine water is also commonly used to check for the presence of an aldehyde group in compounds. In this reaction as well the color of bromine water is changed to colorless from yellow (oxidation process).