Question

Match the reagents required for the given reactions:

I.	Oxidation of primary alcohols to aldehydes	(p)	\[\ce{NaBH4}\]
II.	Butan-2-one to Butan-2-ol	(q)	85% phosphoric acid at 440 K
III.	Bromination of Phenol to 2, 4, 6-Tribromophenol	(r)	PCC
IV.	Dehydration of propan-2-ol propene	(s)	Bromine water

विकल्प

• I - (r), II - (p), III - (s), IV - (q)

• I - (q), II - (r), III - (p), IV - (s)

• I - (s), II - (q), III - (p), IV - (r)

• I - (p), II - (s), III - (r), IV - (q)

Answer 1

I - (r), II - (p), III - (s), IV - (q)

Explanation:

I.	Oxidation of primary alcohols to aldehydes	(r)	PCC
II.	Butan-2-one to Butan-2-ol	(p)	\[\ce{NaBH4}\]
III.	Bromination of Phenol to 2, 4, 6-Tribromophenol	(s)	Bromine water
IV.	Dehydration of propan-2-ol propene	(q)	85% phosphoric acid at 440 K

1. The conversion of primary alcohol to aldehyde is achieved using PCC-Pyridinium chlorochromate, which is notably milder than alternative oxidizing agents such as potassium dichromate or chromic acid. 
2. For conversion of ketone to secondary alcohol, sodium borohydride is used.
3. Bromine water forms a white precipitate of 2, 4, 6-tribromophenol when treated with phenol.
4. 85% phosphoric acid is used for the removal of \[\ce{OH}\] group from secondary alcohol to form an alkene.