Chemistry - Salt Analysis Question with Solution | TestHub

This test is used for the presence of sulphur in any compound. When sodium nitroprusside, react with sulphide ion, $\left(\mathrm{e}.\mathrm{g}.{\mathrm{Na}}_2 \mathrm{S}\right)$ the following reaction takes place

$\begin{array}{ccc}{\mathrm{Na}}_2\mathrm{S}+{\mathrm{Na}}_2\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_5\mathrm{NO}\right]& ⟶& {\mathrm{Na}}_4\left[\mathrm{Fe}{\left(\mathrm{CN}\right)}_5{\mathrm{NO}}_5\right]\\ \left(\mathrm{Sod}. \mathrm{nitroprusside}\right)& & \mathrm{purple} \mathrm{coloration} \left(\mathrm{sod}. \mathrm{thionitroprusside}\right)\end{array}$