Dipole moment of cis-2, 3-dichloro-2 butne is ….. Than the dipole moment of cis1, 2-dichloroethene.

Options

A. more
B. less
C. neither more nor less
D. None of the above

Explanation

To determine the dipole moment of cis-2,3-dichloro-2-butene compared to cis-1,2-dichloroethene, we need to analyze the molecular structure and the arrangement of the chlorine atoms in both compounds.

### Step-by-Step Solution:

1. **Identify the Structures**:
- **Cis-2,3-dichloro-2-butene** has the following structure:
- The butene backbone has a double bond between the second and third carbon atoms.
- The two chlorine atoms are attached to the second and third carbon atoms, both on the same side (cis configuration).
- **Cis-1,2-dichloroethene** has the following structure:
- The ethene backbone has a double bond between the first and second carbon atoms.
- The two chlorine atoms are attached to the first and second carbon atoms, also on the same side (cis configuration).

2. **Analyze the Dipole Moments**:
- The dipole moment is a vector quantity that depends on the magnitude of the charge and the distance between the charges.
- In **cis-2,3-dichloro-2-butene**, the dipole moments of the two C-Cl bonds will add up vectorially because they are oriented in the same direction (due to the cis configuration).
- In **cis-1,2-dichloroethene**, the dipole moments of the two C-Cl bonds will also add up, but the overall dipole moment may be affected by the shorter carbon chain and the proximity of the chlorine atoms.

3. **Compare the Dipole Moments**:
- The dipole moment of **cis-2,3-dichloro-2-butene** is expected to be larger than that of **cis-1,2-dichloroethene** due to the larger molecular size and the greater distance between the chlorine atoms in the butene structure, which enhances the overall dipole moment.
- Therefore, we conclude that the dipole moment of cis-2,3-dichloro-2-butene is greater than that of cis-1,2-dichloroethene.

### Final Answer:
The dipole moment of cis-2,3-dichloro-2-butene is greater than the dipole moment of cis-1,2-dichloroethene.