JEE CHEMISTRY MCQ: GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS

Mixture of chlorides of copper, cadmium, chromium iron and aluminium was dissolved in water acidified with ${HCl}$ and ${H}_2{S}$ gas was passed for a sufficient time. It was filtered boiled and a few drops of nitric acid were added while boiling. To this solution ammonium chloride and sodium hydroxide were added and filtered. The filtrate would give test for