AFOQT Practice Test

Which of the following substances is an example of an acid?

1. Sodium bicarbonate

2. Bleach

3. Vinegar

4. Detergent

The correct answer is: Vinegar

Vinegar is an example of an acid because it contains acetic acid, which gives it its characteristic sour taste and pungent smell. Acids are substances that can donate protons (H⁺ ions) in a chemical reaction and typically have a pH less than 7. Vinegar, with a pH usually around 2 to 3, clearly falls into this category, making it a common household acid used in cooking and cleaning. In contrast, sodium bicarbonate, commonly known as baking soda, is a weak base rather than an acid. Bleach is a strong base, often containing sodium hypochlorite, used for its disinfecting properties. Detergents are generally neutral or slightly basic substances formulated to clean and remove dirt, grease, and stains. Each of these other substances, therefore, does not exhibit the acidic properties that define vinegar.