On the addition of a solution containing `CrO_(4)^(2-)` ions to the solution of `Ba^(2+), Sr^(2+)` and `Ca^(2+)` ions, the precipitate obtained first will be of:

Options

A. `CaCrO_(4)`
B. `SrCrO_(4)`
C. `BaCrO_(4)`
D. a mixture of all the three

Explanation

To solve the question regarding the addition of a solution containing \( \text{CrO}_4^{2-} \) ions to solutions of \( \text{Ba}^{2+} \), \( \text{Sr}^{2+} \), and \( \text{Ca}^{2+} \) ions, we need to analyze the solubility of the chromates formed with each of these cations.

### Step-by-Step Solution:

1. **Identify the Compounds Formed:**
When \( \text{CrO}_4^{2-} \) ions are added to the solutions of \( \text{Ba}^{2+} \), \( \text{Sr}^{2+} \), and \( \text{Ca}^{2+} \), the following chromates can be formed:
- \( \text{BaCrO}_4 \) (Barium Chromate)
- \( \text{SrCrO}_4 \) (Strontium Chromate)
- \( \text{CaCrO}_4 \) (Calcium Chromate)

2. **Check the Solubility of Each Chromate:**
- **Barium Chromate \( \text{BaCrO}_4 \)**: This compound is insoluble in water and will precipitate out of the solution.
- **Strontium Chromate \( \text{SrCrO}_4 \)**: This compound is also insoluble in water and will precipitate, but it is less common than barium chromate.
- **Calcium Chromate \( \text{CaCrO}_4 \)**: This compound is soluble in water, meaning it will not form a precipitate.

3. **Determine the Order of Precipitation:**
Since \( \text{CaCrO}_4 \) is soluble, it will not precipitate. Between \( \text{BaCrO}_4 \) and \( \text{SrCrO}_4 \), \( \text{BaCrO}_4 \) is known to precipitate first due to its lower solubility compared to strontium chromate.

4. **Conclusion:**
The first precipitate that will be formed upon the addition of \( \text{CrO}_4^{2-} \) ions to the solution containing \( \text{Ba}^{2+} \), \( \text{Sr}^{2+} \), and \( \text{Ca}^{2+} \) ions will be \( \text{BaCrO}_4 \).

### Final Answer:
The precipitate obtained first will be \( \text{BaCrO}_4 \) (Barium Chromate).

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