Example of geometrical isomerism is

Options

A. Butan – 2 – ol
B. But – 2 – ene
C. Butan – 1 – ol
D. But – 2 – yne

Answer

To solve the question "Example of geometrical isomerism is," we will analyze the structures of different organic compounds to determine which one exhibits geometrical isomerism.

### Step-by-Step Solution:

1. **Understanding Geometrical Isomerism**:
- Geometrical isomerism occurs in compounds with restricted rotation around a double bond or a ring structure. This leads to different spatial arrangements of groups attached to the carbon atoms.

2. **Analyzing Butane-2-ol**:
- The structure of butane-2-ol is:
\[ CH_3-CH(OH)-CH_2-CH_3 \]
- Since it has a single bond at the carbon with the hydroxyl group, it does not exhibit geometrical isomerism.

3. **Analyzing Butene-2 (But-2-ene)**:
- The structure of but-2-ene is:
\[ CH_3-CH=CH-CH_3 \]
- This compound can exist in two forms: cis (Z) and trans (E).
- **Cis**: Both methyl groups (CH3) on the same side.
- **Trans**: Methyl groups on opposite sides.
- Therefore, but-2-ene exhibits geometrical isomerism.

4. **Analyzing Butane-1-ol**:
- The structure of butane-1-ol is:
\[ CH_2(OH)-CH_2-CH_2-CH_3 \]
- This compound does not have a double bond, hence it cannot exhibit geometrical isomerism.

5. **Analyzing Butyne-2 (But-2-yne)**:
- The structure of butyne-2 is:
\[ CH_3-C≡C-CH_3 \]
- This compound has a triple bond and does not exhibit geometrical isomerism due to the linear arrangement of atoms around the triple bond.

6. **Conclusion**:
- The only compound from the examples that exhibits geometrical isomerism is but-2-ene.

### Final Answer:
The example of geometrical isomerism is **But-2-ene**.