What is the common name for ethanoic acid?

Ethanoic acid is commonly called acetic acid. You find it in vinegar. It gives vinegar its sour taste and smell.

Formic acid comes from ants. Butyric acid smells like rancid butter. Propionic acid is used in food preservation.

Remember: Vinegar contains 5% acetic acid in water. The chemical formula is CH₃COOH.