1. What is Acetic Acid?

Acetic acid, systematically named ethanoic acid, is a colorless liquid organic compound with the chemical formula CH₃COOH. It is the main component of vinegar (apart from water) and gives vinegar its characteristic sour taste and pungent smell.

2. Chemical Structure

The molecular structure of acetic acid consists of:

Structural Features:

• Methyl group (CH₃-) attached to a carboxyl group (-COOH)
• Carboxyl group contains carbonyl (C=O) and hydroxyl (-OH) groups
• Molecular formula: C₂H₄O₂
• Simplified formula: CH₃COOH

3. Physical Properties

Key Properties:

• Molar mass: 60.05 g/mol
• Appearance: Colorless liquid
• Odor: Pungent, vinegar-like
• Density: 1.049 g/cm³
• Melting point: 16.6°C (61.9°F)
• Boiling point: 118.1°C (244.6°F)
• Solubility: Miscible with water, ethanol, ether

4. Uses and Applications

Common Applications:

• Vinegar production (4-8% acetic acid in water)
• Chemical synthesis precursor
• Food preservative and flavoring agent
• Industrial solvent
• Production of vinyl acetate monomer
• Household cleaning agent

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between acetic acid and vinegar?
A: Vinegar is a dilute solution of acetic acid (typically 4-8%) in water, while acetic acid refers to the pure chemical compound.

Q2: Is acetic acid dangerous?
A: Concentrated acetic acid is corrosive and can cause burns, while dilute solutions (like vinegar) are generally safe for consumption and household use.

Q3: What gives acetic acid its sour taste?
A: The hydrogen ions (H⁺) released when acetic acid dissociates in water stimulate sour taste receptors on the tongue.

Q4: Can acetic acid conduct electricity?
A: Pure acetic acid is a poor conductor, but it becomes a weak conductor when dissolved in water due to partial dissociation into ions.

Q5: What is glacial acetic acid?
A: Glacial acetic acid refers to pure, water-free acetic acid that solidifies into ice-like crystals at temperatures below 16.6°C.