Question

Identify the products A and B in the reactions: $R-X + AgCN \longrightarrow A + AgX$ $R-X + KCN \longrightarrow B+ KX$

• A. A = RNC; B = RCN
• B. A = R - CN; B = RCN
• C. A - RNC; B = RNC
• D. A = RCN; B = RNC

Answer 1

Answer: (A)

A = RNC; B = RCN

Answer 2

The products A and B in the reactions can be identified as follows:
$\text{R-X} + \text{AgCN} \rightarrow \text{A} + \text{AgX}$
In this reaction, the cyanide ion ($\text{CN}^-$) acts as a nucleophile and substitutes the leaving group X in $R-X$.
The resulting product A is formed by the attachment of the cyano group$(-CN)$ to the R group, while the silver ion (Ag+) combines with the leaving group X to form AgX.
$\text{R-X} + \text{KCN} \rightarrow \text{B} + \text{KX}$
In this reaction, the cyanide ion $\text{CN}^-$ from KCN also acts as a nucleophile and substitutes the leaving group X in R-X. The resulting product B is formed by the attachment of the cyano group (-CN) to the R group, while the potassium ion (K+) combines with the leaving group X to form KX.
Based on the above reactions, we can conclude that:
$A = RCN$ (cyano group attached to R)
$B = R - CN$ (cyano group attached to R)
Therefore, the correct identification of products A and B in the reactions is (A) $A = \text{RNC}; \quad B = \text{RCN}$