Which of the following molecules will have polar bonds but zero dipole moment ?

Options

A. `O_(2)`
B. `CHCl_(3)`
C. `CF_(4)`
D. none of these

Answer

To determine which molecules have polar bonds but a zero dipole moment, we can follow these steps:

### Step 1: Understand Polar Bonds
- Polar bonds occur when there is a significant difference in electronegativity between the two atoms involved in the bond. This results in a dipole moment where one end of the bond is slightly negative and the other end is slightly positive.

### Step 2: Identify Molecular Geometry
- The geometry of the molecule plays a crucial role in determining the overall dipole moment. If a molecule is symmetrical, the individual dipole moments of the polar bonds can cancel each other out, resulting in a zero dipole moment.

### Step 3: Analyze the Given Molecule (CF4)
- CF4 (Carbon Tetrafluoride) has a tetrahedral geometry. In this molecule, the carbon atom is at the center, and the four fluorine atoms are symmetrically arranged around it.

### Step 4: Determine Symmetry
- Since CF4 is symmetrical, the dipole moments of the four C-F bonds will point in opposite directions and will cancel each other out. Therefore, even though the C-F bonds are polar, the overall dipole moment of the molecule is zero.

### Conclusion
- The answer is CF4, which has polar bonds but a zero dipole moment due to its symmetrical tetrahedral shape.