Q. Copper sulphate solution reacts with KCN and gives
A) $K_{3}\lbrack Cu(CN)_{4}\rbrack$
B) $CuCN$
C) $Cu(CN)_{2}$
D) $K_{2}\lbrack Cu(CN)_{4}\rbrack$
Explanation
(a)
${CuSO}_{4} + 2KCN \longrightarrow \ K_{2}{SO}_{4} + Cu(CN)_{2}$
cupric cyanide
(unstable)
$2Cu(CN)2\ \longrightarrow \ 2CuCN + (CN)_{2}$
white ppt
$3KCN + CuCN\ \longrightarrow K_{3}\lbrack Cu(CN)_{4}\rbrack$
potassium cuprocyanide
(soluble complex)
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.