Acetic acid is a weak acid because

Options

A. It is an organic acid
B. It is a monobasic acid
C. It is unstable
D. It is slightly ionized

Answer

**Step-by-Step Text Solution:**

1. **Definition of Acids**: Acids are substances that can donate protons (H⁺ ions) in a solution. The strength of an acid is determined by its ability to ionize in water.

2. **Strong vs Weak Acids**: Strong acids, like hydrochloric acid (HCl), completely ionize in solution. This means that if you take one mole of HCl, it will dissociate entirely into H⁺ ions and Cl⁻ ions, resulting in a high concentration of H⁺ ions.

3. **Ionization of Acetic Acid**: Acetic acid (CH₃COOH) is considered a weak acid because it does not completely ionize in solution. When acetic acid is dissolved in water, it only partially dissociates into H⁺ ions and acetate ions (CH₃COO⁻).

4. **Equilibrium in Weak Acids**: The dissociation of acetic acid can be represented by the following equilibrium reaction:
\[ \text{CH}_3\text{COOH} \rightleftharpoons \text{H}^+ + \text{CH}_3\text{COO}^- \]
The double arrow indicates that the reaction does not go to completion; instead, it reaches a state of equilibrium where both the reactants and products are present.

5. **Extent of Ionization**: In the case of acetic acid, only about 5-10% of the acid molecules ionize in solution. This means that if you start with one mole of acetic acid, you will get a maximum of 0.1 moles of H⁺ ions, indicating a much lower concentration of H⁺ compared to a strong acid like HCl.

6. **Conclusion**: Because acetic acid only partially ionizes and produces fewer H⁺ ions compared to strong acids, it is classified as a weak acid.

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