Which is not soluble in water

Options

A. `CaCO_(3)`
B. `BaCO_(3)`
C. `SrCO_(3)`
D. All of these

Explanation

To determine which of the given compounds is not soluble in water, we will analyze the solubility of each carbonate mentioned in the options.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given in the question are:
- Calcium carbonate (CaCO₃)
- Barium carbonate (BaCO₃)
- Strontium carbonate (SrCO₃)

2. **Understand Solubility Rules**: In general, carbonates (CO₃²⁻) are mostly insoluble in water, with some exceptions. The carbonates of alkali metals (like sodium and potassium) are soluble, but the carbonates of alkaline earth metals (like calcium, barium, and strontium) are typically insoluble.

3. **Evaluate Each Compound**:
- **Calcium Carbonate (CaCO₃)**: Insoluble in water.
- **Barium Carbonate (BaCO₃)**: Insoluble in water.
- **Strontium Carbonate (SrCO₃)**: Insoluble in water.

4. **Conclusion**: Since all three compounds (calcium carbonate, barium carbonate, and strontium carbonate) are insoluble in water, the correct answer is "all of these."

### Final Answer:
The correct option is **fourth, all of these** (calcium carbonate, barium carbonate, strontium carbonate) are not soluble in water.

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