Explanation of brown ring chemical test ?
Hello ,
Brown ring test :
In brown ring test dilute FeSO4 is addedto an aqueous solution of nitrate ion.Concentrated H2SO4 is then added along the sided of the test tube. A brown ring is observed at the interface between the solution and H2SO4 layers indicates the presence of nitrate ion in the solution
NO3? + 3Fe^+2 + 4H+ -----> NO + 3Fe^3+ + 2H2O
[Fe(H2O)6]^2+ + NO ------> [Fe(H2O)5(NO)]^2+ + H2O