Question

What is the value of $x$ in the $\left[Ni\right(CN{)}_4{]}^x$ complex ion?

• A. $+2$
• B. $-2$
• C. $0$
• D. $+4$

Answer 1

Answer: (B)

$-2$

$CN$ has $-1$ oxidation state and nickel forms complex in $+2$ oxidation state (stable oxidation state).
Thus, $2+4\times (-1)=x$ and $x=-2$.