Which statement best distinguishes electrolytes from non-electrolytes when dissolved in water?

• A. They conduct electricity in aqueous solution.
• B. They have higher melting points.
• C. They are always acids.
• D. They do not dissolve in water.

Answer: (A)

The core idea is that calling a substance an electrolyte hinges on whether its dissolved form produces ions that can carry charge. In water, electrolytes dissociate into mobile ions, so the solution conducts electricity. Non-electrolytes, even if they dissolve, don’t form significant ions, so their solutions don’t conduct well. This is why salts, strong acids, and bases are electrolytes—they break apart into ions and enable current. Non-electrolytes like sugar or alcohol dissolve as neutral molecules and don’t generate the charged carriers needed for conduction. The other statements aren’t reliable distinctions: melting points vary widely among electrolytes, not all electrolytes are acids (salts and bases are also electrolytes), and many electrolytes do dissolve in water, so those aren’t universal rules.