JEE Chemistry 2026 Question with Solution

Given: The question asks the precipitated forms of Ba$^{2+}$ and Ca$^{2+}$ in group analysis of cations.

Find: The correct precipitated forms of these two cations.

In qualitative inorganic analysis, Ba$^{2+}$ and Ca$^{2+}$ belong to the alkaline earth metal group and are separated by selective precipitation.

Both ions are precipitated when ammonium carbonate is added under suitable conditions:

So, Ba$^{2+}$ is precipitated as barium carbonate and Ca$^{2+}$ is precipitated as calcium carbonate.

The other options are incorrect because hydroxides or sulphides of these ions are not the precipitates used in this step of group analysis, and chromate is not the required precipitate for Ca$^{2+}$ here.

Therefore, both are precipitated as carbonates, so the correct option is D.

Given: Four possible precipitated forms are listed for Ba$^{2+}$ and Ca$^{2+}$.

Find: Which option matches qualitative group analysis.

1. Option A: hydroxide & carbonate This is incorrect because Ba$^{2+}$ is not identified in this group as hydroxide.

2. Option B: sulphide & sulphide This is incorrect because sulphide precipitation is not the group separation step for Ba$^{2+}$ and Ca$^{2+}$.

3. Option C: chromate & sulphide This is incorrect because Ca$^{2+}$ is not precipitated as sulphide in this analysis step.

4. Option D: carbonate & carbonate This matches the known qualitative analysis behavior, where both ions form insoluble carbonates.

Therefore, the correct option is D.