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What happens when bromine water is combined with an alkene

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Final answer:

Bromine water reacts with alkenes in a process called halogenation to form a disubstituted alkyl halide, which results in the decolorization of the bromine water.

This reaction is a test for the presence of alkenes and differs from halogenation of alkanes which normally requires UV light or high temperatures.

Step-by-step explanation:

When bromine water is combined with an alkene, a chemical reaction occurs known as halogenation, where the bromine adds across the double bond of the alkene, resulting in the formation of a disubstituted alkyl halide. Bromine water, which is brownish red in color, will decolorize, signaling that the reaction has taken place.

For example, when bromine is added to ethene (an alkene), a disubstituted alkyl halide called 1,2-dibromoethane is formed, highlighting that the alkene has reacted with the bromine.

The disappearance of the brownish red color of bromine is a classic test to confirm the presence of alkenes. This process is an example of halogenation, specifically the addition of a halogen to an unsaturated hydrocarbon.

It is important to note that alkanes can also undergo a halogenation reaction with bromine, but this usually requires ultraviolet light or high temperatures and results in a substitution reaction rather than an addition reaction like with alkenes.

User Matheus Avellar
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