Step 1: Understand what a strong acid is. A strong acid is one that completely breaks apart (dissociates) into ions when dissolved in water.
Step 2: Look at the acids given: HCl, HF, H2CO3, and CH3COOH.
Step 3: Identify which of these acids completely dissociates in water. HCl is known to do this.
Step 4: Recognize that HF (hydrofluoric acid), H2CO3 (carbonic acid), and CH3COOH (acetic acid) do not completely dissociate in water, making them weak acids.
Step 5: Conclude that HCl is the only strong acid among the options provided.
