Question

The oxidation state of $Fe$ in $K_4\left[Fe{\left(CN\right)}_6\right]$ is:

• A. $+3$
• B. $+4$
• C. $+2$
• D. $-2$

Answer 1

Answer: (C)

$+2$

$K_4\left[Fe{\left(CN\right)}_6\right]⟶4K^{+}+\left[Fe\right(CN{)}_6{]}^{4-}$

${\left[Fe{\left(CN\right)}_6\right]}^{4-}$

By charge balance:

$C=M+L$

$-4=M+(-1\times 6)$

$-4=M-6$

$M=+2$