JEE Advanced levelSingle correct optionDifficulty 3 of 3ap049
P and Q are isomers of CX4HX10O. P gives turbidity immediately with Lucas reagent and a negative iodoform test. Q gives turbidity after about 5 minutes and a positive iodoform test. P and Q are, respectively,
Abutan-1-ol and butan-2-ol
B2-methylpropan-1-ol and butan-2-ol
C2-methylpropan-2-ol and butan-1-ol
D2-methylpropan-2-ol and butan-2-ol
Answer: D
Immediate turbidity means a tertiary alcohol, so P is 2-methylpropan-2-ol (no CHX3CH(OH)X− unit, so iodoform negative). Q is secondary and gives iodoform, so it has a CHX3CH(OH)X− unit: butan-2-ol.