Question

When `FeCl_(3)` is added to the sodium extract of an organic compound containing both N and S, the red coloured precipitate is formed due to the formation of
A. `[Fe(CN)_(6)]^(3-)`
B. `[Fe(CNS)]^(2+)`
C. `[Fe(CNS)_(2)]^(+)`
D. `[Fe(CN)_(6)]^(4-)`

Answer 1

Correct Answer - B
When `FeCl_(3)` is added to the sodium extract of an organic compound containing both N and S, a red coloured precipitate of `[Fe(CNS)]^(2+)` is formed.
`NaCNS+FeCl_(3)rarr underset("Red coloured complex")([(Fe(SCN)]Cl_(2))darr)+NaCl`