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Edexcel IGCSE Chemistry · Spec 4.23-4.28

Alkenes & the Bromine Water Test

The alkenes, their reactions, and the bromine water test for unsaturation.

Chemistry revision video

Alkenes & the Bromine Water Test

Spec 4.23-4.28

What you need to know

  • Describe the alkenes and their general formula
  • Describe their addition reactions
  • Use bromine water to test for a carbon-carbon double bond

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Quick check

Answer each question before opening the answer.

What is the general formula of the alkenes and what makes them unsaturated?

CnH2n; they contain a carbon–carbon double bond (C=C).

What is the result of the bromine water test with an alkene?

Bromine water is decolourised (orange to colourless); with an alkane it stays orange.

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