Which of the following compounds will react with bromine water at room temperature?
Show the answer and explanation
Correct answer
B. Ethene
Principle or equation
Alkenes contain a carbon-carbon double bond, which undergoes addition reactions with bromine water, decolorizing it. Alkanes, alcohols, and haloalkanes do not react under these conditions.
Why this answer is correct
Ethene (C2H4) has a double bond; bromine adds across it, forming 1,2-dibromoethane and decolorizing the orange bromine water. Ethane is saturated, ethanol and chloroethane lack reactive double bonds.
Example
Bubble ethene gas into bromine water: the orange color fades to colorless. Ethane does not decolorize bromine water.
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