Which of the following substances is classified as an electrolyte?

• A. NaCl (sodium chloride) dissolved in water
• B. C_6H_{12}O_6 (glucose) dissolved in water
• C. CH_3OH (methanol) dissolved in water
• D. CCl_4 (carbon tetrachloride) in liquid form

Answer: (A)

Verified step by step guidance

1. Understand the definition of an electrolyte: an electrolyte is a substance that, when dissolved in water, dissociates into ions and thus conducts electricity.
2. Examine each substance's behavior in water: determine whether it dissociates into ions or remains as neutral molecules.
3. For NaCl (sodium chloride), recognize that it is an ionic compound that dissociates completely into Na\^{+} and Cl\^{-} ions in water, making it a strong electrolyte.
4. For C_6H_{12}O_6 (glucose) and CH_3OH (methanol), note that these are molecular compounds that dissolve in water but do not dissociate into ions; they remain as neutral molecules and thus are nonelectrolytes or very weak electrolytes.
5. For CCl_4 (carbon tetrachloride), understand that it is a nonpolar molecular liquid that does not dissolve well in water and does not produce ions, so it is not an electrolyte.