Question

Which among the following is not correctly matched with their colour?

• A. $\begin{array}{cc}\text{Compound}& \text{Colour}\\ N{a}_4\left[Fe\right(CN{)}_{5}NOS]& \text{purple}\end{array}$
• B. $\begin{array}{cc}\text{Compound}& \text{Colour}\\ F{e}_4\left[Fe\right(CN{)}_6{]}_3.x{H}_{2}O& \text{Crimson red}\end{array}$
• C. $\begin{array}{cc}\text{Compound}& \text{Colour}\\ \left[Fe\right(SCN){]}^{2+}& \text{Blood red}\end{array}$
• D. $\begin{array}{cc}\text{Compound}& \text{Colour}\\ AgCl& \text{White}\end{array}$

Answer 1

The correct option is B $\begin{array}{cc}\text{Compound}& \text{Colour}\\ F{e}_4\left[Fe\right(CN{)}_6{]}_3.x{H}_{2}O& \text{Crimson red}\end{array}$

$a.\underset{\text{from sodium extracted}}{N{a}_{2}S}+N{a}_2\left[Fe\right(CN{)}_{5}NO]\to \underset{\text{purple colouration}}{N{a}_4\left[Fe\right(CN{)}_{5}NOS]}$
$b.3Fe\left[\right(CN{)}_6{]}^{4-}4F{e}^{3+}\to \underset{\text{Prussian blue}}{F{e}_4\left[Fe\right(CN{)}_6{]}_3.x{H}_{2}O}$
$c.F{e}^{+3}+SC{N}^{-}\to \underset{\text{Ferricthiocynate (Blood red colouration)}}{\left[Fe\right(SCN){]}^{2+}}$
$d.Na+Cl\stackrel{△}{\to }NaCl\stackrel{AgN{O}_3}{\to }\underset{\text{white ppt}}{AgCl}+NaN{O}_3$