The brown ring test for NO2 , and NO3 , is due to the
formation of complex ion with a formula
Answers
Answer:
The brown ring test is the most common nitrate test. In this test solution is treated with iron sulphate and concentrated sulphuric acid. The presence of nitrate ion is detected by the brown ring forms below the aqueous solution and between two layers.
Explanation:
To analyse the presence of nitrate ions in a solution various methods are used, brown ring test is one of the nitrate tests. Brown ring test is the most common nitrate test which is used for the analysis of nitrate ions.
In the brown ring test, the solution is reacted with iron(ll) sulphate and then concentrated sulphuric acid is added to that solution very slowly. This reaction forms a complex ion, which has the formula [Fe(H2O)5NO]2+ . This complex ion forms a brown ring around the test tube. This brown ring formed below the aqueous layer and between the two layers. The formation of this brown ring indicates the presence of nitrate ions in solution.
The reaction takes place as:
2HNO3+ 3H2SO4+ 6FeSO4→ 3Fe2(SO4)3+ 2NO + 4H2O[Fe(H2O)6]SO4+ NO →[Fe(H2O)5NO]SO4BrownRing+ H2O