Which of the following statements is not correct for `SO_(2)` gas?

Options

A. It acts as bleaching agent in moist conditions.
B. Its dilute solution is used as disinfectant.
C. Its molecules have linear geometry.
D. Acidified `KMnO_(4)` is decolourised when `SO_(2)` is passed through it.

Explanation

To determine which statement is not correct for SO₂ gas, we will analyze the properties and characteristics of sulfur dioxide.

### Step 1: Understand the Molecular Structure of SO₂
- **Molecular Formula**: SO₂ consists of one sulfur (S) atom and two oxygen (O) atoms.
- **Shape**: The shape of the SO₂ molecule is bent due to the presence of a lone pair on the sulfur atom, which repels the bonding pairs of electrons.

**Hint**: Remember that the molecular shape can be influenced by lone pairs of electrons.

### Step 2: Determine the Geometry of SO₂
- **Geometry**: The geometry of SO₂ is trigonal planar because it has three regions of electron density (two bonding pairs and one lone pair).
- However, the actual shape is bent due to the lone pair.

**Hint**: Geometry refers to the arrangement of electron pairs, while shape refers to the arrangement of atoms.

### Step 3: Identify the Properties of SO₂
- **Bleaching Agent**: SO₂ acts as a bleaching agent in moist conditions. This is correct.
- **Disinfectant**: A dilute solution of SO₂ is used as a disinfectant. This is also correct.
- **Reducing Agent**: SO₂ is a strong reducing agent and can reduce KMnO₄ (potassium permanganate) from purple to colorless.

**Hint**: Look for common uses of SO₂ in industrial applications.

### Step 4: Analyze the Given Statements
1. **It acts as a bleaching agent in moist conditions** - Correct.
2. **Its dilute solution is used as a disinfectant** - Correct.
3. **Its geometry has a linear geometry** - Incorrect (it has a trigonal planar geometry but a bent shape).
4. **Acidified KMnO₄ is decolorized when SO₂ is passed through it** - Correct.

### Conclusion
The statement that is not correct about SO₂ gas is:
- **Its geometry has a linear geometry.**

### Final Answer
The incorrect statement regarding SO₂ gas is: **Its geometry has a linear geometry.**

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