Which will not show geometrical is isomerism ?1

Options

A. Maleic acid
B. Fumaric acid
C. Cinnamic acid
D. Salicylic acid

Answer

To determine which compound does not show geometrical isomerism, we need to analyze each of the given options based on their structures and the presence of double bonds or restricted rotation around single bonds.

### Step-by-Step Solution:

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

2. **Analyzing Malic Acid**:
- Structure: Malic acid has a double bond between two carbon atoms (C=C) and two carboxylic acid groups (COOH).
- Isomerism: It can exist in two forms: cis (where similar groups are on the same side) and trans (where similar groups are on opposite sides).
- Conclusion: Malic acid shows geometrical isomerism.

3. **Analyzing Cinnamic Acid**:
- Structure: Cinnamic acid also has a double bond between two carbon atoms and is substituted with a phenyl group (C6H5) and a carboxylic acid group.
- Isomerism: Similar to malic acid, it can exist in cis and trans forms.
- Conclusion: Cinnamic acid shows geometrical isomerism.

4. **Analyzing Salicylic Acid**:
- Structure: Salicylic acid has a benzene ring with a hydroxyl group (OH) and a carboxylic acid group (COOH) attached to it.
- Isomerism: The presence of the benzene ring and the nature of the substituents do not allow for geometrical isomerism because there is no double bond or restricted rotation that would lead to different spatial arrangements.
- Conclusion: Salicylic acid does not show geometrical isomerism.

5. **Final Answer**:
- Based on the analysis, the compound that does not show geometrical isomerism is **Salicylic Acid**.