sulphur detection

Question

In Lassaigne's test, sulphur is detected by formation of:

RankGuru · Accepted Answer

1. **Sodium Fusion**: $Na + S 	o Na_2S$ (Sodium sulphide).
2. **Preparation**: The fusion extract is acidified with acetic acid.
3. **The Test**: Lead acetate solution ($ (CH_3COO)_2Pb$) is added to the extract.
4. **Observation**: A distinct **black precipitate** of **Lead Sulphide ($PbS$)** is formed.
5. **Equation**: $S^{2-} + Pb^{2+} 	o PbS \downarrow$.
6. **Alternative**: Sulphur can also be detected by the **Sodium Nitroprusside test**, which gives a deep **violet** coloration (forming $Na_4[Fe(CN)_5NOS]$).

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sulphur detection

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