The given reaction occurs in a car battery when it is used to produce electricity.
`Pb+PbO_(2)+2H_(2)SO_(4)to2PbSO_(4)+2H_(2)O`
Which of the following statements are incorrect about this reaction?
I. Pb is acting as an oxidising agent.
II. `H_(2)SO_(4)` is acting as a reducing agent.
III. The reaction is a precipitation reaction.
IV. `PbO_(2)` oxidises Pb to `PbSO_(4)`.

Options

A. III and IV only
B. I and II only
C. I and III only
D. I, II, III and IV

Answer

To determine which statements are incorrect regarding the given reaction in a car battery, we will analyze each statement based on the principles of oxidation and reduction.

**Given Reaction:**
\[ \text{Pb} + \text{PbO}_2 + 2\text{H}_2\text{SO}_4 \rightarrow 2\text{PbSO}_4 + 2\text{H}_2\text{O} \]

### Step 1: Identify Oxidation and Reduction
- **Oxidation** is the loss of electrons or an increase in oxidation state.
- **Reduction** is the gain of electrons or a decrease in oxidation state.

In this reaction:
- Lead (Pb) starts in the elemental state (oxidation state 0) and ends up in lead sulfate (PbSO₄) with an oxidation state of +2.
- Lead dioxide (PbO₂) has lead in the +4 oxidation state and is reduced to +2 in PbSO₄.

### Step 2: Determine the Roles of Each Component
1. **Lead (Pb)**:
- It is oxidized from 0 to +2, meaning it loses electrons. Thus, Pb acts as a reducing agent, not an oxidizing agent.

2. **Lead Dioxide (PbO₂)**:
- It is reduced from +4 to +2, meaning it gains electrons. Thus, PbO₂ acts as an oxidizing agent.

3. **Sulfuric Acid (H₂SO₄)**:
- It provides the sulfate ions (SO₄²⁻) but does not undergo a change in oxidation state in this reaction. However, it facilitates the reaction and can be considered to have a reducing effect on PbO₂.

### Step 3: Analyze the Statements
- **Statement I**: Pb is acting as an oxidizing agent.
- **Incorrect**: Pb is a reducing agent since it is oxidized.

- **Statement II**: H₂SO₄ is acting as a reducing agent.
- **Incorrect**: H₂SO₄ does not act as a reducing agent; it primarily serves as an electrolyte and does not undergo reduction itself.

- **Statement III**: The reaction is a precipitation reaction.
- **Correct**: PbSO₄ is formed as a solid precipitate.

- **Statement IV**: PbO₂ oxidizes Pb to PbSO₄.
- **Correct**: PbO₂ is reduced while oxidizing Pb to PbSO₄.

### Conclusion
The incorrect statements are:
- Statement I: Pb is acting as an oxidizing agent.
- Statement II: H₂SO₄ is acting as a reducing agent.

### Final Answer
The incorrect statements are I and II.