Which of the following is an example of a strong acid in aqueous solution?

• A. Carbonic acid, H2CO3
• B. Hydrochloric acid, HCl
• C. Acetic acid, CH3COOH
• D. Hydrofluoric acid, HF

Answer: (B)

Verified step by step guidance

1. Understand the definition of a strong acid: a strong acid completely dissociates into its ions in aqueous solution, meaning it releases all of its protons (H\textsuperscript{+}) when dissolved in water.
2. Review the given acids and their typical behavior in water: Carbonic acid (H\_2CO\_3) is a weak acid that partially dissociates; Acetic acid (CH\_3COOH) is also a weak acid with partial dissociation; Hydrofluoric acid (HF) is a weak acid that does not fully dissociate in water.
3. Recognize that Hydrochloric acid (HCl) is a classic example of a strong acid because it completely dissociates into H\textsuperscript{+} and Cl\textsuperscript{−} ions in aqueous solution.
4. Confirm that the strong acid among the options is Hydrochloric acid (HCl) based on its complete ionization property.
5. Summarize that the key to identifying a strong acid is its complete dissociation in water, which applies to HCl but not to the other acids listed.