Alcohols, Phenols and Ethers

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Statement I is true but Statement II is false
2. Both Statement I and Statement II are true
3. Both Statement I and Statement II are false
4. Statement I is false but Statement II is true

Answer

(1) Statement I is true but Statement II is false

Solution

Acidity: p-nitrophenol (pKa 7.1) > o-nitrophenol (7.2) > m-nitrophenol (8.3)

∵ p-NO2 stabilises the phenoxide by −R and −I; o: intramolecular H-bond holds the H; m: only −I

⇒ Statement-I is true

Lucas reagent (conc. HCl + anhyd. ZnCl2): 3° alcohol — turbidity at once; 2° — in about 5 min; 1° (ethanol) — no turbidity at room temperature

⇒ Statement-II is false

Answer: (1)