Match the column
`{:("Column I (Acid)","Column II " (pK_(a) "Value")),("(A) HCOOH","(p) 1.73"),("(B) " CH_(3)CO OH,"(q) 3.74"),("(C) PhCOOH","(r) 4.17"),("(D) " (CO OH)_(2),"(s) 4.75"):}`

Explanation

To solve the problem of matching the acids in Column I with their respective pKa values in Column II, we need to analyze the acidity of each acid based on their structures and the influence of substituents on their acidity.

### Step-by-Step Solution:

1. **Identify the Acids:**
- (A) HCOOH (Formic Acid)
- (B) CH₃COOH (Acetic Acid)
- (C) PhCOOH (Benzoic Acid)
- (D) (COOH)₂ (Oxalic Acid)

2. **Understand pKa Values:**
- pKa is a measure of the strength of an acid; the lower the pKa value, the stronger the acid.
- We need to match each acid with its corresponding pKa value from the options provided.

3. **Analyze Each Acid:**
- **HCOOH (Formic Acid)**: This is a strong acid among the given options due to the absence of electron-donating groups. It has a pKa of approximately 3.75.
- **CH₃COOH (Acetic Acid)**: The presence of the methyl group (CH₃) is an electron-donating group, which makes it less acidic than formic acid. Its pKa is around 4.76.
- **PhCOOH (Benzoic Acid)**: The phenyl group (Ph) is less electron-donating than the methyl group, making benzoic acid more acidic than acetic acid. Its pKa is about 4.20.
- **(COOH)₂ (Oxalic Acid)**: Oxalic acid is a dicarboxylic acid and is generally more acidic than the monocarboxylic acids listed. Its pKa is around 1.25.

4. **Match Acids with pKa Values:**
- (A) HCOOH → (q) 3.74
- (B) CH₃COOH → (s) 4.75
- (C) PhCOOH → (r) 4.17
- (D) (COOH)₂ → (p) 1.73

### Final Matching:
- (A) HCOOH → (q) 3.74
- (B) CH₃COOH → (s) 4.75
- (C) PhCOOH → (r) 4.17
- (D) (COOH)₂ → (p) 1.73