Formaldehyde (CH₂O) and acetic acid (C₂H₄O₂) have the same empirical formula, which is CH₂O. This means they have the same ratio of atoms in their molecules. However, they are different because they have different molecular formulas and different structures, leading to different properties.

Here's a breakdown:

1. Molecular Formula:

* Formaldehyde: CH₂O

* Acetic acid: C₂H₄O₂

2. Structure:

* Formaldehyde: A simple molecule with a carbon atom double-bonded to an oxygen atom and single-bonded to two hydrogen atoms.

* Acetic acid: A more complex molecule with a carbon atom double-bonded to an oxygen atom, single-bonded to a hydroxyl group (OH), and a methyl group (CH₃).

3. Properties:

* Formaldehyde: A colorless gas with a pungent odor, used in manufacturing resins and plastics. It is highly reactive and toxic.

* Acetic acid: A colorless liquid with a sour taste and vinegar-like odor. It is a weak acid used in food, pharmaceuticals, and chemical industries.

In summary, while formaldehyde and acetic acid share the same empirical formula (CH₂O), their different molecular formulas and structures result in distinct properties and applications.