Read the following passage and answer questions.

Nucleophiles attack at that part of the substrate molecule which is electron deficient. The reaction in which a nucleophile replaces already existing nucleophile in a molecule is called nucleophilic substitution reaction. Haloalkanes are substrates in these reactions. In this type of reaction, a nucleophile reacts with haloalkane (the substrate) having a partial positive charge on the carbon atom bonded to halogen. A substitution reaction takes place and halogen atom, called leaving group departs as halide ion. Since the substitution reaction is initiated by a nucleophile, it is called nucleophilic substitution reaction.

When AgCN reacts with R-X, what is the major product?

Isonitrile

The correct answer is Option (3) → Isonitrile

CN⁻ is an ambident nucleophile. Attack can occur through:

• Carbon → nitrile • Nitrogen → isonitrile

With AgCN, nitrogen attacks.

Reaction R–X + AgCN → R–NC

Product formed = Isonitrile

Option 1: Alcohol - Alcohol forms with OH⁻ nucleophile. Not present here.

Option 2: Ether - Requires alkoxide ion. Not applicable.

Option 3: Isonitrile-  AgCN is covalent. Carbon is bonded to Ag, leaving nitrogen free. Nitrogen attacks → forms isonitrile (R–NC).

Option 4: Nitrile- Forms when KCN is used (ionic CN⁻ attacks through carbon). Not formed here