Which of the following compounds is a weak electrolyte?

• A. HCl (hydrochloric acid)
• B. KNO3 (potassium nitrate)
• C. NaCl (sodium chloride)
• D. CH3COOH (acetic acid)

Answer: (D)

Verified step by step guidance

1. Understand what an electrolyte is: an electrolyte is a substance that produces ions and conducts electricity when dissolved in water.
2. Recognize that strong electrolytes completely dissociate into ions in solution, while weak electrolytes only partially dissociate.
3. Identify the nature of each compound: HCl is a strong acid and strong electrolyte, KNO3 and NaCl are salts that fully dissociate and are strong electrolytes.
4. Recall that CH3COOH (acetic acid) is a weak acid and only partially ionizes in water, making it a weak electrolyte.
5. Conclude that among the given options, CH3COOH is the weak electrolyte because it does not fully dissociate into ions in solution.