Which reagent is used to remove `SO_(4)^(2-) or Cl^(Theta)` from water

Options

A. `NaOH`
B. `Pb(NO_(3))_(2)`
C. `BaSO_(4)`
D. `KOH`

Explanation

To determine which reagent can be used to remove sulfate ions (SO₄²⁻) and chloride ions (Cl⁻) from water, we will analyze the provided options step by step.

### Step 1: Analyze NaOH
- **Reaction with sulfate ions:**
\[ \text{NaOH} + \text{SO}_4^{2-} \rightarrow \text{Na}_2\text{SO}_4 + \text{OH}^- \]
Sodium sulfate (Na₂SO₄) is soluble in water.

- **Reaction with chloride ions:**
\[ \text{NaOH} + \text{Cl}^- \rightarrow \text{NaCl} + \text{OH}^- \]
Sodium chloride (NaCl) is also soluble in water.

**Conclusion:** NaOH cannot be used to remove sulfate or chloride ions as both products are soluble.

### Step 2: Analyze Lead Nitrate (Pb(NO₃)₂)
- **Reaction with sulfate ions:**
\[ \text{Pb(NO}_3\text{)}_2 + \text{SO}_4^{2-} \rightarrow \text{PbSO}_4 \downarrow + 2\text{NO}_3^- \]
Lead sulfate (PbSO₄) is insoluble in water and precipitates out.

- **Reaction with chloride ions:**
\[ \text{Pb(NO}_3\text{)}_2 + 2\text{Cl}^- \rightarrow \text{PbCl}_2 \downarrow + 2\text{NO}_3^- \]
Lead chloride (PbCl₂) is also insoluble in water and precipitates out.

**Conclusion:** Lead nitrate can effectively remove both sulfate and chloride ions from water as both products are insoluble.

### Step 3: Analyze Barium Sulfate (BaSO₄)
- **Reaction with sulfate ions:**
\[ \text{BaSO}_4 + \text{SO}_4^{2-} \rightarrow \text{No Reaction} \]
No reaction occurs since BaSO₄ is already a sulfate.

- **Reaction with chloride ions:**
\[ \text{BaSO}_4 + 2\text{Cl}^- \rightarrow \text{BaCl}_2 + \text{SO}_4^{2-} \]
Barium chloride (BaCl₂) is soluble in water.

**Conclusion:** Barium sulfate cannot be used to remove sulfate ions and is ineffective for chloride ions.

### Step 4: Analyze Potassium Hydroxide (KOH)
- **Reaction with sulfate ions:**
\[ \text{KOH} + \text{SO}_4^{2-} \rightarrow \text{K}_2\text{SO}_4 + \text{H}_2\text{O} \]
Potassium sulfate (K₂SO₄) is soluble in water.

- **Reaction with chloride ions:**
\[ \text{KOH} + \text{Cl}^- \rightarrow \text{KCl} + \text{OH}^- \]
Potassium chloride (KCl) is also soluble in water.

**Conclusion:** KOH cannot be used to remove sulfate or chloride ions as both products are soluble.

### Final Answer:
The reagent that can be used to remove sulfate ions and chloride ions from water is **Lead Nitrate (Pb(NO₃)₂)**.

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