Which one of the following substances can be classified as a nonelectrolyte?

• A. KNO3 (potassium nitrate)
• B. HCl (hydrochloric acid)
• C. C6H12O6 (glucose)
• D. NaCl (sodium chloride)

Answer: (C)

Verified step by step guidance

1. Understand the definition of an electrolyte: an electrolyte is a substance that dissociates into ions when dissolved in water, allowing the solution to conduct electricity.
2. Identify the nature of each substance: KNO3, HCl, and NaCl are ionic compounds or strong acids that dissociate completely into ions in aqueous solution, making them strong electrolytes.
3. Recognize that C6H12O6 (glucose) is a molecular compound that dissolves in water but does not dissociate into ions; it remains as intact molecules.
4. Conclude that since glucose does not produce ions in solution, it cannot conduct electricity and is therefore classified as a nonelectrolyte.
5. Summarize that nonelectrolytes are typically covalent compounds like sugars, alcohols, and other molecular substances that dissolve without ionizing.