Which of the following does not give ppt with `CrO_(4)^(-2)`

Options

A. `Ca^(+2)`
B. `Sr^(+2)`
C. `Pb^(+2)`
D. `Ba^(+2)`

Explanation

To solve the question "Which of the following does not give ppt with CrO4^(-2)?", we will analyze the solubility of various compounds formed with chromate ions (CrO4^(-2)) and determine which one does not precipitate.

### Step-by-step Solution:

1. **Understand the Concept of Precipitation**:
- Precipitation occurs when the product of the concentrations of the ions in solution exceeds the solubility product (Ksp) of the compound formed. If Ksp is high, the compound is more soluble and less likely to precipitate.

2. **Identify the Compounds**:
- The question likely provides a list of ions or compounds. For this solution, we will assume the common alkaline earth metals and lead ions are included in the options.

3. **Analyze the Solubility of Chromates**:
- The solubility of chromates varies among different alkaline earth metals:
- **Barium Chromate (BaCrO4)**: Low solubility (low Ksp).
- **Strontium Chromate (SrCrO4)**: Moderate solubility.
- **Calcium Chromate (CaCrO4)**: Higher solubility (higher Ksp).
- Lead Chromate (PbCrO4) also has low solubility.

4. **Determine Which Ion Does Not Precipitate**:
- Among the alkaline earth metals, as we move from calcium to barium, the solubility decreases. Calcium chromate is more soluble compared to barium and strontium chromates.
- Therefore, calcium chromate (CaCrO4) is less likely to precipitate compared to the others.

5. **Conclusion**:
- Based on the analysis, the ion that does not give a precipitate with CrO4^(-2) is **Calcium (Ca^2+)**.

### Final Answer:
- **Calcium (Ca^2+)** does not give a precipitate with CrO4^(-2).