Question

Freshly prepared solution of sodium nitroprusside is added to the sodium extract. Appearance of a deep violet colour indicates the presence of.

• A. Nitrogen1
• B. Sulphur
• C. Both nitrogen and sulphur
• D. Halogen

Answer 1

Answer: (B)

Sulphur

Answer 2

:$Na_{2}S + \underset{\begin{aligned} & Sod.nitroprusside \\ & \end{aligned}}{Na_{2}\lbrack Fe(CN)_{5}(NO)}\rbrack \rightarrow \underset{\begin{aligned} & Sod.thionitroprusside \\ & (Violet) \\ & \end{aligned}}{Na_{4}\lbrack Fe(CN)_{5}(NOS)}\rbrack$