1. What Is Acetic Acid?

Acetic acid, systematically named ethanoic acid, is an organic compound with the chemical formula CH₃COOH. It is a colorless liquid that when undiluted is called glacial acetic acid. Acetic acid is the main component of vinegar (apart from water) and has a distinctive sour taste and pungent smell.

2. Chemical Formula Explanation

The chemical formula can be represented in two common ways:

Where:

• \( CH₃COOH \) — Structural formula showing the methyl group and carboxylic acid functional group
• \( C₂H₄O₂ \) — Molecular formula indicating the exact number of atoms
• Molecular Weight — 60.05 g/mol
• Density — 1.05 g/cm³
• Boiling Point — 118-119°C

Explanation: The formula represents a simple carboxylic acid consisting of a methyl group attached to a carboxyl functional group.

3. Molecular Structure

Details: Acetic acid molecules form dimers (pairs) in the liquid phase and in non-aqueous solvents due to hydrogen bonding between the carbonyl oxygen and the hydroxyl group. The crystal structure shows chains of molecules interconnected by hydrogen bonds.

4. Common Applications

Applications: Used in the production of vinyl acetate monomer, acetic anhydride, ester production, as a solvent, in food industry as vinegar, and in household cleaning products.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between CH₃COOH and C₂H₄O₂?
A: CH₃COOH shows the structural arrangement, while C₂H₄O₂ shows the molecular composition. Both represent the same compound.

Q2: Why is acetic acid called a weak acid?
A: It only partially dissociates in solution, with a pKa of 4.76, making it a weak acid compared to strong mineral acids.

Q3: What concentration is typically found in vinegar?
A: Household vinegar typically contains 4-8% acetic acid by volume, while commercial vinegar may contain higher concentrations.

Q4: Is acetic acid dangerous?
A: In concentrated form, it is corrosive and can cause burns. Dilute solutions like vinegar are generally safe for consumption and household use.

Q5: What are the industrial production methods?
A: Mainly produced by methanol carbonylation, but also by bacterial fermentation of ethanol (vinegar production) and oxidation of acetaldehyde.