Question

In general tests of Ba$^{2+}$ and Ca$^{2+}$ give the respective tests as:

• A. Chromate, Sulphate
• B. Sulphite, Sulphate
• C. Hydroxide, Carbonate
• D. Carbonate, Carbonate

Hint:

Group IV cations give carbonate precipitates with ammonium carbonate.

Answer 1

The Correct Option is D

Step 1: Identify the group reagent.
Ba$^{2+}$ and Ca$^{2+}$ belong to alkaline earth metals and are analysed using group reagent:
\[ (NH_4)_2CO_3 \text{ in presence of } NH_4OH \text{ and } NH_4Cl \]
Step 2: Formation of precipitates.
Both Ba$^{2+}$ and Ca$^{2+}$ form insoluble carbonates:
\[ Ba^{2+} + CO_3^{2-} \rightarrow BaCO_3 \ (\text{white ppt}) \] \[ Ca^{2+} + CO_3^{2-} \rightarrow CaCO_3 \ (\text{white ppt}) \]
Step 3: Conclusion.
Thus, both ions give carbonate test.