Which of the following compounds will show geometrical isomerism?

Options

A. 2-butene
B. propene
C. 1-phenyl ethene
D. 2-methyl-2-butene

Explanation

To determine which of the given compounds will show geometrical isomerism, we need to analyze each compound based on the criteria for geometrical isomerism.

### Step-by-Step Solution:

1. **Understanding Geometrical Isomerism**:
- Geometrical isomerism occurs in compounds with a carbon-carbon double bond (C=C) where each carbon atom of the double bond has two different groups attached to it. This allows for the formation of cis (same side) and trans (opposite sides) isomers.

2. **Analyzing Each Compound**:
- We will look at each compound provided in the question to see if they meet the criteria for geometrical isomerism.

3. **Compound 1: 2-Butene (C4H8)**:
- Structure: CH3-CH=CH-CH3
- On the double bond, one carbon has a CH3 group and a H atom, while the other carbon has a CH3 group and a H atom. Since the groups are different, geometrical isomerism is possible.
- **Cis Form**: CH3 on the same side.
- **Trans Form**: CH3 on opposite sides.

4. **Compound 2: Propene (C3H6)**:
- Structure: CH3-CH=CH2
- On the double bond, one carbon has a CH3 group and the other has two H atoms. Since both groups on one carbon are the same (H), geometrical isomerism is not possible.

5. **Compound 3: 1-Phenyl Ethene (C8H8)**:
- Structure: C6H5-CH=CH2
- On the double bond, one carbon has a phenyl group (C6H5) and the other has two H atoms. Since both groups on one carbon are the same (H), geometrical isomerism is not possible.

6. **Compound 4: 2-Methyl-2-Butene (C5H10)**:
- Structure: CH3-C(CH3)=CH2
- On the double bond, one carbon has two CH3 groups and the other has a H atom. Since both groups on one carbon are the same (CH3), geometrical isomerism is not possible.

### Conclusion:
- Among the compounds analyzed, only **2-Butene** shows geometrical isomerism. Therefore, the answer to the question is **2-Butene**.