NTA Abhyas JEE Main2020ChemistryAlcohols Phenols and EthersPractice
Place the following alcohols in decreasing order of rate of dehydration with concentrated H 2 SO 4 : 1. CH 3 CH 2 CH(OH)CH 2 CH 2 CH 3 2. (CH 3 ) 2 C(OH)CH 2 CH 2 CH 3 3. (CH 3 ) 2 C(OH)CH(CH 3 ) 2 4. CH 3 CH 2 CH(OH)CH(CH 3 ) 2 5. CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 OH
Options
- A3 > 2 > 4 > 5 > 1
- B3 > 2 > 4 > 1 > 5
- C3 > 2 > 1 > 4 > 5
- D3 > 2 > 1 > 5 > 4
Correct answer
B. 3 > 2 > 4 > 1 > 5
Step-by-step solution
The alcohols (3) and (2) are both 3 o , but alcohol (3) gives a more substituted alkene. Alcohol (4) and (1) are both 2 o , but alcohol (4) can give a more substituted alkene and alcohol (5) is 1 o . Rate of dehydration of alcohols with concentrated H 2 SO 4 follows the order 3 o > 2 o > 1 o .