Question

Cation of salt A when treated in flame gives apple green colour. When salt A is heated with Chromate solution gives yellow precipitate & when salt is heated with conc $HNO_3$ & Ammionium molybdate it gives canary yellow ppt. Salt A contains :

• A. $Ba^{+2}$ and $PO_4^{3-}$
• B. $Ca^{+2}$ and $SO_4^{2-}$
• C. $Ba^{+2}$ and $SO_4^{2-}$
• D. $Sr^{+2}$ and $PO_4^{3-}$

Answer 1

The Correct Option is A

Qualitative analysis of inorganic salts using flame tests and specific confirmatory reagents.
1. Identify the Cation:
Flame test color = Apple green. This is a characteristic test for $Ba^{2+}$.

2. Identify the Anion (Test 1):
Heating with Chromate solution gives a yellow precipitate ($BaCrO_4$). This confirms the presence of $Ba^{2+}$.

3. Identify the Anion (Test 2):
Heating with concentrated $HNO_3$ and ammonium molybdate gives a canary yellow precipitate. This is the standard confirmatory test for Phosphate ion ($PO_4^{3-}$).

Conclusion:
Salt A contains $Ba^{2+}$ and $PO_4^{3-}$. Option (1) is correct.