A. FeSO4.No
B. FeSO4.No2
C. FeSO4.No3
D. FeSO4.N2o
¨ The brown ring test is a qualitative test used to detect the presence of nitrates (NO3-) in a given sample. It is a specific variation of the nitrate test, which involves the addition of ferrous sulfate (FeSO4) and concentrated sulfuric acid (H2SO4) to the sample.
¨ If nitrates are present in the sample, they will be reduced to nitric oxide (NO) by the FeSO4 under the acidic conditions. The nitric oxide (NO) then reacts with the iron(II) sulfate (FeSO4) to form a brown-colored complex, FeSO4.NO, which appears as a brown ring at the interface between the sample and the acid. The reaction is as follows:
¨ 3NO + FeSO4 → FeSO4.NO + 2NO2
¨ The brown ring test is a simple and reliable test for the detection of nitrates, and it is commonly used in environmental analysis and food safety testing. However, it should be noted that other nitrogen-containing compounds, such as nitrites (NO2-) and some organic compounds, may also give a positive result in the test, so additional confirmatory tests may be necessary.
Submitted by :- Jamil Ahmed