Question

Which of the following hydrocarbons can decolourise bromine water and which cannot? Why?
C₆H₁₂, C₆H₁₄, C₆H₁₀

Answer 1

C₆H₁₂ (Hexene) and C₆H₁₀ (Hexyne or Cyclohexene ) are the hydrocarbons which can decolourize bromine water, as they are unsaturated. Bromine undergo addition reactions with unsaturated compounds like alkenes and alkynes containing a double or a triple bond. When bromine water is added to an unsaturated compound, the former gets added to the latter, thereby turning colourless from its reddish brown colour.
C₆H₁₄ (Hexane) is a hydrocarbon which cannot decolourize bromine water because it is a saturated compound (alkane). Saturated co