Question

An aqueous solution containing ferrous cyanide and potassium cyanide in the molar ratio of 1 : 4 is evaporated. The solid obtained is re-dissolved in water. The ion present in this solution is

• A. $\left[Fe\right(CN{)}_6{]}^{4-}$
• B. $\left[Fe\right(CN{)}_6{]}^{3-}$
• C. $\left[Fe\right(CN{)}_3]$
• D. $F{e}^{3+}$

Answer 1

The correct option is A $\left[Fe\right(CN{)}_6{]}^{4-}$

The solid obtained is
$FeS{O}_4+KCN\to K_4\left[Fe\right(CN{)}_6]\Rightarrow 4K^{+}+[Fe(CN{)}_6{]}^{4-}$