Dichloro ethene shows

Options

A. Geometrical isomerism
B. Position isomerism
C. Metamerism
D. Chain isomerism

Answer

To analyze the isomerism of dichloroethene, we need to understand its structure and the types of isomerism it can exhibit. Let's break it down step by step.

### Step 1: Understand the Structure of Dichloroethene
Dichloroethene (C2H2Cl2) can exist in two structural forms based on the positioning of the chlorine atoms. The two main structures are:
1. 1,1-Dichloroethene (both Cl atoms on the same carbon)
2. 1,2-Dichloroethene (Cl atoms on different carbons)

### Step 2: Identify the Types of Isomerism
1. **Position Isomerism**: This occurs when the position of the chlorine atoms changes. In our case, 1,1-dichloroethene and 1,2-dichloroethene are positional isomers.
2. **Geometrical Isomerism**: This occurs in 1,2-dichloroethene due to the presence of a double bond. The two geometrical forms are:
- **Cis Isomer**: Both chlorine atoms are on the same side of the double bond.
- **Trans Isomer**: The chlorine atoms are on opposite sides of the double bond.

### Step 3: Conclusion on Isomerism
Dichloroethene can show:
- **Position Isomerism**: between 1,1-dichloroethene and 1,2-dichloroethene.
- **Geometrical Isomerism**: in 1,2-dichloroethene, leading to cis and trans forms.

### Final Answer
Dichloroethene shows both position isomerism and geometrical isomerism.

---