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–COOH. 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.

Given below are two statements about R-CN and R-NC and their reactions. Choose the correct option.

Q. 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–COOH.

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.

(A) Both Statement I and Statement II are false

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

(D) Both Statement I and Statement II are true

Correct Answer: Statement I is false but Statement II is true

Explanation

Statement I:

The dipole moment of R–NC (isocyanide) is actually greater than that of R–CN (cyanide) due to the reversed polarity of the C–N bond.

Also, R–NC does NOT undergo hydrolysis to give carboxylic acid under acidic conditions. Only R–CN undergoes hydrolysis to give R–COOH.

Hence, Statement I is false.

Statement II:

R–CN + H₂O / H⁺ → R–COOH

The carboxylic acid formed reacts with thionyl chloride:

R–COOH + SOCl₂ → R–COCl

Acid chloride reacts with ammonia:

R–COCl + NH₃ → R–CONH₂ (compound x)

Amide undergoes Hofmann bromamide reaction:

R–CONH₂ + NaOCl/NaOH → R–NH₂

Primary amine on treatment with CHCl₃/KOH/Δ undergoes carbylamine reaction:

R–NH₂ → R–NC

Hence, Statement II is true.

Therefore, the correct option is: Statement I is false but Statement II is true.

Explanation

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