Which of the following compounds forms a powerful acid and also contains a halogen?

• A. CH_3COOH
• B. H_2SO_4
• C. HCl
• D. HNO_3

Answer: (C)

Verified step by step guidance

1. Identify the compounds listed and their general properties: CH_3COOH (acetic acid), H_2SO_4 (sulfuric acid), HCl (hydrochloric acid), and HNO_3 (nitric acid).
2. Recall that a powerful acid is one that completely dissociates in water, known as a strong acid.
3. Recognize that halogens are elements in Group 17 of the periodic table, such as fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
4. Check which compound contains a halogen atom: CH_3COOH contains no halogen, H_2SO_4 contains sulfur and oxygen, HCl contains chlorine (a halogen), and HNO_3 contains nitrogen and oxygen.
5. Conclude that HCl is the compound that both contains a halogen and is a strong acid, making it the correct answer.