Haloakanes react with KCN to form alkyl cyanides as main product while AgCN forms isocyanides as the chief product . Explain .

Explanation

KCN is predominantly ionic and provides cyanide ions in solution. Although both carbon and nitrogen atoms are in a position to donate electron pairs, the attack takes place mainly through carbon atom and not through nitrogen atom since `C-C` bond is more stable than `C-N` bond. However, `AgCN` is mainly covalent in nature and nitrogen is free to donate electron pair forming isocyanide as the main product.