Salt analysis | Chromyl chloride test |Qualitative Analysis

Chromyl chloride test is for the chloride ions .The salts which produce chloride ion ,give positive test for this test. The salts like mercurous and mercuric chloride and chlorides of gold and silver do not give this test because these are covalent chloride . In the salt first we add potassium dichromate and from the side of the test tube, add concentrated H2SO4. A brown colour vapour is produced which is called chromyl chloride. Now it is passed into aq NaOH ,then yellow coloured solution of sodium chromate is formed. If lead acetate is added in this solution, It turns into yellow precipitate due to formation of lead chromate. In another test, if you take the same chromate ion where the yellow colour solution was formed and add little alcohol and some H2O2 whose concentration is nearly 10%,then a blue coloured solution is formed. This is due to formation of chromium (VI) peroxide CrO5 . These two tests confirms the presence of chloride ion in the given salt. #Chromylchloride Test #Salt Analysis #Qualitative Analysis