Question

What happens when ethanol is treated with phosphorus tribromide?

Answer 1

When ethanol (CH₃CH₂OH) is treated with phosphorus tribromide (PBr₃), it undergoes a substitution reaction, resulting in the conversion of the hydroxyl group (–OH) into a bromine atom (Br). This produces ethyl bromide (C₂H₅Br).

\[\ce{\underset{ethanol}{CH3CH2OH} + \underset{tribromide}{\underset{phosphorus}{PBr3}} -> \underset{ethyl bromide}{CH3CH2Br} + \underset{phosphorous acid}{H3PO3}}\]