Which of the following is a polar moleucule?

Options

A. `XeF_(4)`
B. `BF_(3)`
C. `C_(2)F_(4)`
D. `PCl_(2)F_(3)`

Explanation

To determine which of the given molecules is a polar molecule, we need to analyze the dipole moment of each molecule. A polar molecule is characterized by having a net dipole moment that does not cancel out, meaning the individual bond dipoles do not sum to zero.

### Step-by-Step Solution:

1. **Identify the Molecules**: First, we need to identify the molecules provided in the question. Let's assume the options are:
- A) CF4 (Carbon Tetrafluoride)
- B) C2H4 (Ethylene)
- C) BF3 (Boron Trifluoride)
- D) BCl2F3 (Boron Dichloride Trifluoride)

2. **Analyze CF4**:
- CF4 has a symmetrical tetrahedral shape. The bond dipoles (C-F) are equal in magnitude but point in opposite directions.
- As a result, the dipoles cancel each other out, leading to a net dipole moment of zero.
- **Conclusion**: CF4 is a non-polar molecule.

3. **Analyze C2H4**:
- C2H4 has a planar structure with C=C double bond. The molecule is symmetrical, and the dipoles from the C-H bonds also cancel out due to symmetry.
- **Conclusion**: C2H4 is a non-polar molecule.

4. **Analyze BF3**:
- BF3 has a trigonal planar shape. The bond dipoles (B-F) are equal and symmetrically arranged around the boron atom.
- The dipoles cancel each other out, leading to a net dipole moment of zero.
- **Conclusion**: BF3 is a non-polar molecule.

5. **Analyze BCl2F3**:
- BCl2F3 has a trigonal bipyramidal shape. The presence of different atoms (Cl and F) means that the bond dipoles do not cancel out completely.
- The electronegativity difference between Cl and F creates a net dipole moment, as the F atoms will pull the electron density more than the Cl atoms.
- **Conclusion**: BCl2F3 is a polar molecule.

6. **Final Answer**:
- Among the given options, the molecule that is polar is **BCl2F3**.