Which is not easily precipitated for aqueous solution ?

Options

A. `Cl^(-)`
B. `SO_(4)^(2-)`
C. `NO_(3)^(-)`
D. `CO_(3)^(2-)`

Answer

To determine which anion is not easily precipitated from an aqueous solution, we will analyze the precipitation reactions of the given anions one by one.

### Step-by-Step Solution:

1. **Identify the Anions**: The anions provided are:
- Chloride ion (Cl⁻)
- Sulfate ion (SO₄²⁻)
- Nitrate ion (NO₃⁻)
- Carbonate ion (CO₃²⁻)

2. **Analyze Chloride Ion (Cl⁻)**:
- When silver ions (Ag⁺) react with chloride ions (Cl⁻), they form silver chloride (AgCl), which is a white precipitate.
- **Conclusion**: Chloride ions are easily precipitated.

3. **Analyze Sulfate Ion (SO₄²⁻)**:
- When barium ions (Ba²⁺) react with sulfate ions (SO₄²⁻), they form barium sulfate (BaSO₄), which is also a white precipitate.
- **Conclusion**: Sulfate ions are easily precipitated.

4. **Analyze Nitrate Ion (NO₃⁻)**:
- Most nitrates are soluble in water. For example, when magnesium ions (Mg²⁺) react with nitrate ions (NO₃⁻), they form magnesium nitrate (Mg(NO₃)₂), which remains in solution.
- Other examples include sodium nitrate (NaNO₃) and silver nitrate (AgNO₃), both of which are soluble.
- **Conclusion**: Nitrate ions do not easily precipitate.

5. **Analyze Carbonate Ion (CO₃²⁻)**:
- When calcium ions (Ca²⁺) react with carbonate ions (CO₃²⁻), they form calcium carbonate (CaCO₃), which is a white precipitate.
- **Conclusion**: Carbonate ions are easily precipitated.

6. **Final Conclusion**:
- After analyzing all the anions, we find that the nitrate ion (NO₃⁻) is the only anion that does not easily precipitate in aqueous solution.

### Answer:
The anion that is not easily precipitated from an aqueous solution is the **nitrate ion (NO₃⁻)**.