Austen Tech REACTION WITH Br2 IN CH2Cl2 AND AQUEOUS SOLUTION OF Br2 CHEMICAL TEST :
Used to identify the presence of C-C double bond in alkene or C-C triple bond in alkyne Purpose : Observation : General equations: C C Reagent and condition : Br2 in CH2Cl2 or Br2 (aq) CH2Cl2 Reddish brown colour of bromine decolourised. + Br2 + Br2 (aq) 1. REACTION WITH Br2 in CH2Cl2 2. REACTION WITH Br2 (aq) C C C C OH Br C C Br Br
EXERCISE: Propose a chemical test to differentiate between propene and cyclopropane. State the observation and write the reaction equations involved. ANSWER : + Br2 CH (aq) 3CH=CH2 CH3CH(OH)CH2Br propene Reddish brown colour of bromine decolourised. No reaction cyclopropane Reddish brown colour of bromine remain unchanged. + Br2 (aq)