JEE Main 2026 · 24 January · evening · Single correct · +4 / −1

Given below are two statements :
Statement I : The dipole moment of R-CN is greater than R-NC and R-NC can
undergo hydrolysis under acidic medium to produce R-C(∥)(O)-OH .
Statement II : R-CN hydrolyses under acidic medium to produce a compound which on treatment with SOCl₂, followed by the addition of NH₃ gives another compound (x). This compound (x) on treatment with NaOCl/NaOH gives a product, that on treatment with CHCl₃/KOH/Δ produces R-NC
In the light of the above statements, choose the correct answer from the options given below

  1. (a) Both Statement I and Statement II are false
  2. (b) Statement I is false but Statement II is true
  3. (c) Statement I is true but Statement II is false
  4. (d) Both Statement I and Statement II are true
Answer and solution

Answer (b) Statement I is false but Statement II is true

Solution

Chemistry ma’am · 3 steps

An isocyanide hydrolyses to an amine and formic acid, never to RCOOH, so one wrong half sinks Statement I.

  1. Check Statement I. The dipole comparison is fine: alkyl cyanides are more polar than alkyl isocyanides. But acidic hydrolysis of an isocyanide breaks the C=N link and gives R-NH₂ + HCOOH, not RCOOH. One false part makes the whole statement false.
  2. Follow Statement II. Track each reagent in turn. NaOCl/NaOH is a hypohalite in alkali, so it does the Hofmann bromamide job on the amide. This step removes one carbon, which is exactly why the final R matches the starting R.
    ReagentProductReaction
    H₃O⁺ on R-CNR-COOHnitrile hydrolysis
    SOCl₂, then NH₃R-CONH₂ (x)acid chloride, then amide
    NaOCl/NaOHR-NH₂Hofmann degradation, loses one C
    CHCl₃/KOH, heatR-NCcarbylamine reaction
  3. So. Statement I is false and Statement II is true, which is option (b).

The idea to keep. Hydrolysis keeps the atom bonded to R: cyanides keep C and give RCOOH, isocyanides keep N and give RNH₂. Amide plus hypohalite in alkali gives an amine with one carbon fewer.

Answer from the NTA final answer key. Solution by PrepWiser.

Study Amines & Diazonium Salts

Asked about 170 times in JEE Main since 2020. This question is from 2026.