Question

When $KCN$(excess) is added to a $C{u}^{2+}$, final species formed is $\left[Cu\right(CN{)}_4{]}^{3-}$.

If true enter 1, else enter 0.

Answer 1

Reaction sequence is as follows:

${Cu}^{2+}+2KCN\to 2K+\left[Cu\right(CN{)}_2]$

$Cu(CN{)}_2\to C{u}_2(CN{)}_2+NC-CN$

$C{u}_2(CN{)}_2+6KCN\to 2K_3[Cu\left(CN{)}_4\right]$

Hence, when excess KCN is added to ${Cu}^{2+}$, final species fromed is $\left[Cu\right(CN{)}_4{]}^{3-}$.