JEE Main202127 Jul 2021Evening ShiftChemistryPractical ChemistryActual
To an aqueous solution containing ions such as Al 3 + , Zn 2 + , Ca 2 + , Fe 3 + , Ni 2 + , Ba 2 + and Cu 2 + was added conc . HCl , followed by H 2 S . The total number of cations precipitated during this reaction is/are :
Options
- A1
- B3
- C4
- D2
Correct answer
A. 1
Step-by-step solution
Al 3 + and Fe 3 + sulphides hydrolyse in water. Ni 2 + and Zn 2 + require basic medium with H 2   S to form precipitate. Ca 2 + and Ba 2 + sulphides are also soluble. only Cu 2 + can form the precipitate with H 2 S in the acidic medium.