Attachment of vinyl group or phenyl group directly to carboxylic acid group has effect on the acidic character of that carboxylic acid. Explain. 

Explanation

To understand how the attachment of a vinyl group (−CH=CH2) or a phenyl group (−C6H5) directly to a carboxylic acid group affects its acidic character, we need to analyze the factors that influence acidity in carboxylic acids.

### Step-by-Step Solution:

1. **Understanding Carboxylic Acids**:
- Carboxylic acids have the general formula RCOOH, where R can be hydrogen or a hydrocarbon group. The acidic character of carboxylic acids is primarily due to the ability of the carboxyl group (−COOH) to donate a proton (H+).

2. **Effect of Substituents**:
...