JEE MainChemistryPractical Chemistry
An inorganic salt solution gives a white precipitate when treated with ( NH ₄)₂ CO ₃ in the presence of NH ₄ Cl and NH ₄ OH . The white precipitate is filtered and dissolved in dilute acetic acid. When aqueous potassium chromate ( K ₂ CrO ₄ ) is added to this acidic solution, a yellow precipitate is formed. Identify the cation present in the salt.
Options
- ABa ²⁺
- BSr ²⁺
- CCa ²⁺
- DPb ²⁺
Correct answer
A. Ba ²⁺
Step-by-step solution
The formation of a white precipitate upon the addition of ( NH ₄)₂ CO ₃ in the presence of NH ₄ Cl and NH ₄ OH indicates the presence of a Group V cation ( Ba ²⁺ , Sr ²⁺ , or Ca ²⁺ ). The white precipitate is the metal carbonate ( MCO ₃ ), which dissolves in dilute acetic acid to form the corresponding soluble metal acetate. Among the Group V cations, only Ba ²⁺ forms a yellow precipitate of barium chromate ( BaCrO ₄ ) upon the addition of aqueous K ₂ CrO ₄ . Sr ²⁺ and Ca ²⁺ do not precipitate with chromate under t