Brown ring test is used to detect

(a) Iodide
(b) Nitrate
(c) Iron
(d) Bromide

A common nitrate test, known as the brown ring test can be performed by adding iron(II) sulfate to a solution of a nitrate, then slowly adding concentrated sulfuric acid such that the acid forms a layer below the aqueous solution.
A nitrate test is a chemical test used to determine the presence of nitrate ion in solution.
Ring test is used for confirming $NO^{−3}$ ion in the compound.
edited Mar 20