Question

Identify the major product formed when phenol reacts with bromine water.

• A. Bromobenzene
• B. 2,4,6-tribromophenol
• C. o-bromophenol
• D. p-bromophenol

Hint:

Phenol reacts very rapidly with bromine water without a catalyst and forms 2,4,6-tribromophenol as a white precipitate.

Answer 1

The Correct Option is B

Concept: Phenol contains an \( -OH \) group attached to the benzene ring. The \( -OH \) group is:

• Electron donating
• Strongly activating
• Ortho and para directing

Thus, electrophilic substitution occurs readily at the ortho and para positions.
Step 1: {Reaction with bromine water.} When phenol reacts with bromine water: \[ C_6H_5OH + 3Br_2 \rightarrow C_6H_2Br_3OH + 3HBr \]
Step 2: {Substitution positions.} Because phenol strongly activates the ring, bromination occurs at: \[ 2\text{-position},\;4\text{-position},\;6\text{-position} \]
Step 3: {Major product.} The product formed is: \[ 2,4,6-tribromophenol \] This compound forms as a white precipitate in bromine water.