Among the following the molecule possessing highest dipole moment is

Options

A. `CO_2`
B. `BF_3`
C. `SO_2`
D. trans-2-butene

Explanation

To determine which molecule possesses the highest dipole moment among CO2, BF3, SO2, and trans-butene, we can analyze the molecular geometry and the electronegativity of the atoms involved in each molecule.

### Step-by-Step Solution:

1. **Analyze CO2 (Carbon Dioxide)**:
- CO2 has a linear structure with the carbon atom in the center and oxygen atoms on either side.
- The electronegativity of oxygen is higher than that of carbon, which means each C=O bond has a dipole moment directed towards the oxygen.
- However, since CO2 is linear, the two dipole moments cancel each other out.
- **Conclusion**: The dipole moment of CO2 is zero.

**Hint**: Check the molecular shape and symmetry to see if dipole moments cancel out.

2. **Analyze BF3 (Boron Trifluoride)**:
- BF3 has a trigonal planar structure with boron in the center and three fluorine atoms at the corners.
- Each B-F bond has a dipole moment directed towards the fluorine atoms due to their higher electronegativity.
- However, the symmetry of the trigonal planar shape means that the dipole moments also cancel each other out.
- **Conclusion**: The dipole moment of BF3 is zero.

**Hint**: Consider the geometry and symmetry of the molecule to evaluate the resultant dipole moment.

3. **Analyze SO2 (Sulfur Dioxide)**:
- SO2 has a bent shape due to the presence of a lone pair on the sulfur atom.
- The dipole moments of the S=O bonds are directed towards the oxygen atoms, and because of the bent shape, they do not cancel out completely.
- The presence of the lone pair also contributes to the overall dipole moment.
- **Conclusion**: SO2 has a non-zero dipole moment.

**Hint**: Look for lone pairs and molecular shape that can affect the dipole moment.

4. **Analyze Trans-butene**:
- Trans-butene is an alkene with a double bond between two carbon atoms and has a symmetrical structure.
- The molecule has two methyl (CH3) groups on either side of the double bond, which means the dipole moments of the C-H and C-C bonds will cancel out.
- **Conclusion**: The dipole moment of trans-butene is zero.

**Hint**: Identify if the molecule is symmetrical and how that affects the dipole moment.

### Final Conclusion:
Among CO2, BF3, SO2, and trans-butene, the molecule with the highest dipole moment is **SO2**.