Which of the following reagent does not oxidize HCl ?

Options

A. `PbO_(2)`
B. conc. `H_(2)SO_(4)`
C. `MnO_(2)`
D. `K_(2)Cr_(2)O_(7)//H^(-)`

Explanation

To determine which reagent does not oxidize HCl, we can follow these steps:

### Step 1: Understand the nature of HCl
HCl can be dissociated into its ions:
\[ \text{HCl} \rightarrow \text{H}^+ + \text{Cl}^- \]
Here, Cl⁻ is a weak reducing agent.

### Step 2: Identify strong oxidizing agents
Since Cl⁻ can be oxidized, we need to identify which of the given reagents are strong oxidizing agents. The reagents provided are:
- A) PbO₂
- B) H₂SO₄ (concentrated)
- C) MnO₂
- D) K₂Cr₂O₇

### Step 3: Analyze each reagent
- **PbO₂**: This is a strong oxidizing agent and can oxidize Cl⁻.
- **H₂SO₄ (concentrated)**: This is not considered a strong oxidizing agent in this context and will not oxidize Cl⁻.
- **MnO₂**: This is also a strong oxidizing agent and can oxidize Cl⁻.
- **K₂Cr₂O₇**: This is a strong oxidizing agent and can oxidize Cl⁻.

### Step 4: Conclusion
From the analysis, we can see that:
- A (PbO₂), C (MnO₂), and D (K₂Cr₂O₇) are strong oxidizing agents that can oxidize HCl.
- B (H₂SO₄) is not a strong oxidizing agent and does not oxidize HCl.

Thus, the answer is:
**B) H₂SO₄ (concentrated)** does not oxidize HCl.

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