Question is based on following passage:
Methyl nitrile is hydrolysed to carboxylic acid in the presence of \(H^+\) or \(OH^-\) as catalyst. An intermediate compound [A] is formed during this reaction.
What is not true regarding the compound [B]?
(A) They are higher boiling liquids than aldehydes and ketones due to extensive H-bonding.
(B) They are insoluble in benzene
(C) They produce alkane when heated with soda lime
(D) produces \(CO_2\) when treated with \(NaHCO_3\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (B) only
Note: None of the given options was correct in the NTA question paper. To provide additional question practice to the students, the question has been slightly modified so that the question has one clear answer.
[B] is ethanoic acid, a carboxylic acid. Each statement checked against the book:
(A) They are higher boiling liquids than aldehydes and ketones due to extensive H-bonding. — True for [B]. Carboxylic acids exist as hydrogen-bonded dimers, so they boil higher than aldehydes and ketones of similar mass.
(B) They are insoluble in benzene — Not true for [B]. Carboxylic acids are not insoluble in benzene: they dissolve in less polar organic solvents such as benzene, ether, alcohol and chloroform (extract below).
(C) They produce alkane when heated with soda lime — True for [B]. The book states this reaction for the sodium salts; with soda lime (NaOH and CaO) the acid is first converted to its salt, which then loses \( \ce{CO2} \):
\( \displaystyle \ce{RCOONa} \xrightarrow[\Delta]{\ce{NaOH + CaO}} \ce{R-H + Na2CO3} \)
(D) produces \( \ce{CO2} \) when treated with \( \ce{NaHCO3} \) — True for [B]. This is the usual test for carboxylic acids:
\( \displaystyle \ce{RCOOH + NaHCO3 -> RCOONa + H2O + CO2 ^} \)
NCERT (2026-27 edition):
Physical Properties – …
