Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R: In the light of the above statements, choose the correct answer from the options given below:
- A is false but R is true.
- Both A and R are true but R is NOT the correct explanation of A.
- Both A and R are true and R is the correct explanation of A.
- A is true but R is false.
Answer
(2) Both A and R are true but R is NOT the correct explanation of A.
Solution
As nucleophile: O–H bond breaks; the O of R–OH attacks an electrophile, e.g. R-OH + R'COOH H+ R'COOR + H2O
As electrophile: C–O bond breaks; protonated alcohol R- OH2 is attacked by a nucleophile, e.g. R-OH + HBr R-Br + H2O
⇒ A is true
2R-OH + 2Na 2R-ONa + H2 ⇒ R is true
∵ R shows the acidic nature of alcohols, not their nucleophilic / electrophilic behaviour ⇒ R does not explain A
Answer: (2)