For the Compounds : (A) H3C-CH2-O-CH2-CH2-CH3 (B) H3C-CH2-CH2-CH2-CH3 (C) CH3-CH2- O \|C-CH2-CH3 (D) H3C- OH |CH-CH2-CH2-CH3 The increasing order of boiling point is : Choose the correct answer from the options given below :
- (D) < (C) < (A) < (B)
- (B) < (A) < (C) < (D)
- (A) < (B) < (C) < (D)
- (B) < (A) < (D) < (C)
Answer
(2) (B) < (A) < (C) < (D)
Solution
Similar molar masses (72–88) ⇒ b.p. decided by the intermolecular forces:
(B) pentane: only weak London forces ⇒ lowest (309 K)
(A) ether: weak dipole–dipole (C–O–C) ⇒ (A) > (B) (337 K)
(C) ketone: strong dipole–dipole (polar C=O) ⇒ (C) > (A) (375 K)
(D) alcohol: intermolecular H-bonding ⇒ highest (392 K)
∴ (B) < (A) < (C) < (D)
Answer: (2)