BITSAT2013ChemistryPractical ChemistryActual
A mixture of chlorides of copper, cadmium, chromium, iron and aluminium was dissolved in water acidified with HCl and hydrogen sulphide gas was passed for 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 filterate shall give test for.
Options
- ASodium and iron
- BSodium and aluminium
- CAluminium and iron
- DSodium, iron, cadmium and Al
Correct answer
B. Sodium and aluminium
Step-by-step solution
CuS and CdS are precipitated by H ₂ ~S . Hydroxide of Al will pass into the solution in the form of NaAlO ₂ being amphoteric in nature. Hence filtrate will give test for sodium and aluminium.