Increasing order of acidic character among the following molecules will be

Options

A. `CH_(3)COOH lt H_(2)SO_(4) lt H_(2)CO_(3)`
B. `CH_(3)COOH lt H_(2)CO_(3) lt H_(2)SO_(4)`
C. `H_(2)CO_(3) lt CH_(3)COOH lt H_(2)SO_(4)`
D. `H_(2)SO_(4) lt H_(2)CO_(3) lt CH_(3)COOH`

Answer

To determine the increasing order of acidic character among the given molecules (acetic acid, sulfuric acid, and carbonic acid), we will analyze each acid based on its ability to donate protons (H⁺) and the stability of its conjugate base.

### Step-by-Step Solution:

1. **Identify the Acids**:
- Acetic Acid (CH₃COOH)
- Sulfuric Acid (H₂SO₄)
- Carbonic Acid (H₂CO₃)

2. **Understand Acid Strength**:
- The strength of an acid is determined by its ability to dissociate in water to release protons (H⁺). Strong acids completely dissociate, while weak acids only partially dissociate.

3. **Analyze Sulfuric Acid (H₂SO₄)**:
- H₂SO₄ is a strong acid that completely dissociates in aqueous solution:
\[ H₂SO₄ \rightarrow H⁺ + HSO₄⁻ \]
- It can further dissociate:
\[ HSO₄⁻ \rightarrow H⁺ + SO₄^{2-} \]
- Due to complete dissociation and the stability of its conjugate base (SO₄²⁻), H₂SO₄ is the strongest acid among the three.

4. **Analyze Acetic Acid (CH₃COOH)**:
- Acetic acid is a weak acid that partially dissociates:
\[ CH₃COOH \rightleftharpoons H⁺ + CH₃COO⁻ \]
- The acetate ion (CH₃COO⁻) has two resonance structures, which provides some stability, but it is still weaker than sulfuric acid.

5. **Analyze Carbonic Acid (H₂CO₃)**:
- Carbonic acid also partially dissociates:
\[ H₂CO₃ \rightleftharpoons H⁺ + HCO₃⁻ \]
- The bicarbonate ion (HCO₃⁻) has resonance structures, but the presence of two hydroxyl (OH) groups in carbonic acid donates electron density, making it less acidic compared to acetic acid.

6. **Rank the Acids**:
- Based on the above analysis, we rank the acids in increasing order of acidic strength:
- Carbonic Acid (H₂CO₃) - weakest
- Acetic Acid (CH₃COOH) - moderate
- Sulfuric Acid (H₂SO₄) - strongest

### Final Order:
The increasing order of acidic character is:
**H₂CO₃ < CH₃COOH < H₂SO₄**