1. What is Acetic Acid?

Acetic acid is a simple carboxylic acid and the main component of vinegar (after water). It is a weak acid with the chemical formula CH₃COOH and is an important chemical reagent and industrial chemical.

2. Chemical Formula and Structure

The molecular formula of acetic acid is:

Structural Features:

• Contains a methyl group (CH₃-)
• Contains a carboxyl group (-COOH)
• Molecular weight: 60.05 g/mol
• Simplest carboxylic acid after formic acid

3. Key Properties

Physical Properties:

• Molecular Weight: 60.05 g/mol
• Boiling Point: 118°C
• Melting Point: 16.6°C
• Density: 1.049 g/cm³
• Appearance: Colorless liquid

Chemical Properties:

• pK_a: 4.76
• Weak acid characteristics
• Forms acetate salts with bases
• Undergoes typical carboxylic acid reactions

4. Applications and Uses

Industrial Uses: Production of vinyl acetate monomer, acetic anhydride, ester production, and as solvent.

Food Industry: Main component of vinegar, food preservative, flavoring agent.

Household Uses: Cleaning agent, descaling agent, cooking ingredient.

5. Frequently Asked Questions (FAQ)

Q1: Why is acetic acid considered a weak acid?
A: Acetic acid has a pK_a of 4.76, meaning it only partially dissociates in water, classifying it as a weak acid compared to strong acids like HCl.

Q2: What is the difference between acetic acid and vinegar?
A: Vinegar typically contains 4-8% acetic acid by volume, with the remainder being water and trace chemicals that give it flavor.

Q3: Is acetic acid dangerous?
A: Concentrated acetic acid is corrosive and can cause burns, while diluted forms like vinegar are safe for consumption and household use.

Q4: What are acetate salts?
A: Acetate salts are formed when acetic acid reacts with bases, such as sodium acetate (CH₃COONa) from reaction with sodium hydroxide.

Q5: How is acetic acid produced industrially?
A: Mainly through methanol carbonylation, bacterial fermentation, and oxidation of acetaldehyde.