Question

Primary and secondary valencies of $Cu$ in $\left[Cu{\left(N{H}_3\right)}_4\right]S{O}_4$ is

• A. 4,4
• B. 2,4
• C. 4,1
• D. 4,2

Answer 1

Answer: (B)

$\left[Cu{\left(N{H}_3\right)}_4\right]S{O}_4\Rightarrow {\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}+S{O}_4^{2-}$
$\Rightarrow$ Primary valency $=2$
$Cu$ is bonded to $4,N{H}_3$ ligands.
$\Rightarrow$ Secondary valency $=4$