Soda extract of a salt solution in acidified with excess of dil `CH_(2)COOH` and `CaCI_(2)` soin is added A white ppt insolable in `CH_(3)COOH` confurm of

Options

A. `C_(2)O_(4)^(2-)`
B. `CO_(3)^(2-)`
C. `HCO_(3)^(Theta)`
D. `S_(2)O_(3)^(2-)`

Answer

To solve the problem, we need to analyze the situation step by step:

### Step-by-Step Solution:

1. **Understanding the Problem**:
We have a soda extract of a salt solution that is acidified with excess dilute acetic acid (CH₃COOH), and then calcium chloride (CaCl₂) solution is added. A white precipitate (ppt) is formed that is insoluble in acetic acid. We need to identify the anion that corresponds to this precipitate.

2. **Identifying Possible Anions**:
The question suggests that we are looking for an anion that forms a white precipitate with calcium ions (Ca²⁺) and is insoluble in acetic acid. Common anions that form precipitates with calcium include:
- Oxalate (C₂O₄²⁻)
- Carbonate (CO₃²⁻)
- Phosphate (PO₄³⁻)
- Sulfide (S²⁻)

3. **Reactions with Acetic Acid**:
We need to check the solubility of the calcium salts formed with each anion in acetic acid:
- **Calcium Oxalate (CaC₂O₄)**: This salt is known to be insoluble in acetic acid.
- **Calcium Carbonate (CaCO₃)**: This salt reacts with acetic acid to form calcium acetate (soluble).
- **Calcium Hydrogen Carbonate (Ca(HCO₃)₂)**: This also reacts with acetic acid to form soluble calcium acetate.
- **Calcium Sulfide (CaS)**: This reacts with acetic acid to form soluble calcium acetate.

4. **Conclusion**:
Among the anions considered, only the oxalate ion (C₂O₄²⁻) forms a white precipitate (calcium oxalate) that is insoluble in acetic acid. Therefore, the answer to the question is that the white precipitate confirms the presence of the oxalate ion.

### Final Answer:
The white precipitate insoluble in acetic acid confirms the presence of the **oxalate ion (C₂O₄²⁻)**.

---