Out of the following compounds which one will have zero dipole moment ?

Options

A. Chloromethane
B. Dichloromethane
C. Trichloromethane
D. Tetrachloromethane

Answer

To determine which compound has a zero dipole moment among the given options, we need to analyze the molecular structures and the arrangement of the polar bonds in each compound. The compounds provided are:

1. Chloromethane (CH3Cl)
2. Dichloromethane (CH2Cl2)
3. Trichloromethane (CHCl3)
4. Tetrachloromethane (CCl4)

### Step-by-Step Solution:

**Step 1: Analyze Chloromethane (CH3Cl)**
- Structure: The molecule has one chlorine atom and three hydrogen atoms.
- The dipole moment of the C-H bonds points towards carbon, while the dipole moment of the C-Cl bond points towards chlorine.
- Since the dipole moments do not cancel out, chloromethane has a net dipole moment.
- **Conclusion**: Chloromethane does not have zero dipole moment.

**Step 2: Analyze Dichloromethane (CH2Cl2)**
- Structure: The molecule has two chlorine atoms and two hydrogen atoms.
- The dipole moments of the C-H bonds point towards carbon, while the dipole moments of the C-Cl bonds point towards chlorine.
- The dipole moments do not cancel out completely due to the unequal number of polar bonds, leading to a net dipole moment.
- **Conclusion**: Dichloromethane does not have zero dipole moment.

**Step 3: Analyze Trichloromethane (CHCl3)**
- Structure: The molecule has three chlorine atoms and one hydrogen atom.
- The dipole moments of the C-Cl bonds point towards chlorine, while the dipole moment of the C-H bond points towards carbon.
- The three C-Cl dipole moments dominate and do not cancel out with the C-H bond, resulting in a significant net dipole moment.
- **Conclusion**: Trichloromethane does not have zero dipole moment.

**Step 4: Analyze Tetrachloromethane (CCl4)**
- Structure: The molecule has four chlorine atoms and no hydrogen atoms.
- The dipole moments of all C-Cl bonds point towards chlorine.
- The symmetry of the molecule means that the dipole moments of each bond cancel each other out completely.
- **Conclusion**: Tetrachloromethane has zero dipole moment.

### Final Answer:
The compound that has zero dipole moment is **tetrachloromethane (CCl4)**.

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