Question

Reaction of ethyne with HCN, in the presence of $Ba{{(CN)}_{2}}$ is:

• A. electrophillic addition reaction
• B. nucleophillic addition reaction
• C. free radical addition reaction
• D. electrophillic substitution reaction

Answer 1

Answer: (B)

nucleophillic addition reaction

Answer 2

This reaction is an example of neucleo-phillic addition, in which $C{{N}^{-}}$ attacks the triple bond of acetylene. $\underset{CH}{\overset{CH}{\mathop{|||}}}\,\xrightarrow{{}}\underset{{}^{\delta -}CH}{\overset{{}^{\delta +}CH}{\mathop{||}}}\,\xrightarrow{{{H}^{+}}C{{N}^{-}}}\underset{C{{H}_{2}}}{\overset{CHCN}{\mathop{||}}}\,$