brown ring test

Question

Brown ring test is confirmatory for:

RankGuru · Accepted Answer

The **Brown Ring Test** is highly sensitive for detecting the **Nitrate ($NO_3^-$)** ion.
1. Solution containing nitrate is mixed with fresh **Ferrous sulfate ($FeSO_4$)**.
2. Concentrated $H_2SO_4$ is added carefully along the sides of the test tube.
3. **Result**: A **brown ring** forms at the junction of the two liquid layers.
- **Chemical Identity**: The ring is due to the formation of the complex **$[Fe(H_2O)_5NO]^{2+}$** (Nitroso-ferrous sulfate). The nitrate is reduced to nitrous oxide ($NO$) by $Fe^{2+}$, which kemudian coordinates with another $Fe^{2+}$ ion.

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brown ring test

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