Which species in the given below has a coordinated bond ?

Options

A. `CH_4`
B. `SO_3^(2-)`
C. `NH_3`
D. `CO_2`

Answer

To determine which species has a coordinate bond, we need to understand the definition of a coordinate bond and analyze each given species. A coordinate bond (or dative bond) occurs when one atom donates a pair of electrons to another atom that does not have a pair to share.

### Step-by-Step Solution:

1. **Identify the Species**: The species we need to analyze are CH₄, SO₃²⁻, NH₃, and CO₂.

2. **Analyze CH₄ (Methane)**:
- The central atom is carbon (C).
- Carbon forms four single bonds with hydrogen atoms and has no lone pairs.
- **Conclusion**: CH₄ does not have a coordinate bond.

3. **Analyze SO₃²⁻ (Sulfite Ion)**:
- The central atom is sulfur (S).
- Sulfur has six valence electrons and can form bonds with oxygen atoms.
- In the sulfite ion, sulfur has two lone pairs and can donate one of these lone pairs to an oxygen atom, forming a coordinate bond.
- **Conclusion**: SO₃²⁻ can form a coordinate bond.

4. **Analyze NH₃ (Ammonia)**:
- The central atom is nitrogen (N).
- Nitrogen has one lone pair and forms three single bonds with hydrogen atoms.
- While nitrogen has a lone pair, it is already involved in bonding with hydrogen and cannot form a coordinate bond with another atom in this context.
- **Conclusion**: NH₃ does not have a coordinate bond in this context.

5. **Analyze CO₂ (Carbon Dioxide)**:
- The central atom is carbon (C).
- Carbon forms two double bonds with oxygen atoms and has no lone pairs.
- **Conclusion**: CO₂ does not have a coordinate bond.

### Final Answer:
The species that has a coordinate bond is **SO₃²⁻ (Sulfite Ion)**.

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