The halogenoalkane is heated under reflux with a solution of sodium or potassium hydroxide. In this example, 2-bromopropane is converted into propan-2-ol. The other common method to make alcholes is a substitution reaction, the halogen atom is replaced by an -OH group to give an alcohol. The effect of this is that there are bound to be some alcohols which it is impossible to make by reacting alkenes with steam because the addition would be the wrong way around. If you add a molecule H-X across a carbon-carbon double bond, the hydrogen nearly always gets attached to the carbon with the most hydrogens on it already - in this case the CH2 rather than the CH. You might expect to get either propan-1-ol or propan-2-ol depending on which way around the water adds to the double bond. In principle, there are two different alcohols which might be formed: The reason that there is a problem with some alcohols is well illustrated with trying to make an alcohol from propene, CH 3CH=CH 2. The catalyst used and the reaction conditions will vary from alcohol to alcohol. Some - but not all - other alcohols can be made by similar reactions. The catalyst used is solid silicon dioxide coated with phosphoric(V) acid.

There are two primary methods to make alcohols in the laboratory: Hydration of an alkene and hydrolysis of an alkyl halide.Įthanol is manufactured by reacting ethene with steam. (An old name, emphasizing its slight acidity, was carbolic acid.) Phenol is a white crystalline compound that has a distinctive (“hospital smell”) odor.

The parent compound, C 6H 5OH, is itself called phenol.

Caffeine molecule space group