An aqueous solution of a salt ‘x’ turns blood red on treatment with $SC{N}^{-}$ and blue on treatment with $K_4\left[Fe{\left(CN\right)}_6\right].$ The compound ‘x’ also give a positive chromyl chloride test. The salt ‘x’ is ____ .

$F{e}^{+3}$ cation gives blood red colour with $SC{N}^{-1}$ and blue colour with $K_4\left[Fe{\left(CN\right)}_6\right]$

$\begin{array}{l}F{e^{3+}}_{\left(aq\right)}+SC{N}^{-}\underset{ }{\rightleftarrows }{\left[FeSCN\right]}^{2+}\\ PaleyellowBloodred\end{array}$

$\begin{array}{l}F{e^{3+}}_{\left(aq\right)}+K_4\left[Fe{\left(CN\right)}_6\right]\underset{ }{\to }F{e}_4{\left[Fe{\left(CN\right)}_6\right]}_3\\ PaleyellowBlue\end{array}$

$C{l}^{-}$ anion undergoes chromyl chloride test. Hence, the salt $\text{'}X\text{'}$ is $FeC{l}_3$