When a solution of mixture having two inorganic salts was treated...

The brown ring test is a typical nitrate test that involves adding iron(II) sulphate to a nitrate solution, then slowly adding strong sulfuric acid until the acid forms a layer below the aqueous solution. The existence of the nitrate ion will be shown by the formation of a brown ring at the junction of the two layers. Dark brown ring is formed in the confirmatory test of ${NO}_{3}^{-}$ − ions. Deep red precipitate with ${FeCl}_{3}$ is formed in the presence of ${CH}_{3}{COO}^{-}$ ions.