What is an example of a strong acid?

A strong acid is defined as an acid that completely dissociates into its ions in aqueous solution. In this case, sulfuric acid is considered a strong acid because it ionizes completely in water, releasing hydrogen ions (H⁺) and sulfate ions (SO₄²⁻). This complete dissociation is characteristic of strong acids, leading to a high concentration of H⁺ ions in the solution, which contributes to its strong acidic properties.

In contrast, the other acids listed do not completely dissociate in solution. Acetic acid, citric acid, and carbonic acid are all classified as weak acids because they only partially ionize, meaning that they establish an equilibrium between undissociated molecules and ions, resulting in a lower concentration of H⁺ ions in solution. This difference in dissociation is why sulfuric acid is identified as an example of a strong acid, making it the correct answer.