Which of these substances, when dissolved in water, is a strong electrolyte? (a) ammonia (b) hydrofluoric acid (c) folic acid (d) sodium nitrate (e) sucrose
The Correct Answer and Explanation is:
ChatGPT said:
Correct Answer: (d) sodium nitrate
Explanation:
When a substance dissolves in water, it can behave in one of three ways: as a strong electrolyte, weak electrolyte, or nonelectrolyte. This classification depends on the extent to which the substance dissociates into ions in aqueous solution. A strong electrolyte is a substance that completely dissociates into its constituent ions in water, conducting electricity very well.
Let’s examine each option:
(a) Ammonia (NH₃):
Ammonia is a weak base. When dissolved in water, it reacts partially with water to form ammonium (NH₄⁺) and hydroxide (OH⁻) ions. However, this reaction is reversible and does not proceed to completion, so ammonia is a weak electrolyte.
(b) Hydrofluoric acid (HF):
Hydrofluoric acid is a weak acid. Unlike strong acids like HCl or HNO₃, HF only partially ionizes in water. This limited ionization makes HF a weak electrolyte.
(c) Folic acid:
Folic acid is a weak organic acid, and in water, it does not ionize completely. It is therefore a weak electrolyte or in some cases can act as a nonelectrolyte, depending on concentration and pH.
(d) Sodium nitrate (NaNO₃):
Sodium nitrate is an ionic compound composed of Na⁺ and NO₃⁻ ions. When it dissolves in water, it completely dissociates into these ions. Since this dissociation is 100%, sodium nitrate is a strong electrolyte. Solutions of NaNO₃ conduct electricity very well due to the presence of free-moving ions.
(e) Sucrose (C₁₂H₂₂O₁₁):
Sucrose is a covalent compound (a sugar), and when it dissolves in water, it does not break into ions. It simply dissolves as whole molecules. Therefore, sucrose is a nonelectrolyte.
Conclusion:
Only sodium nitrate (d) completely dissociates into ions in water, making it a strong electrolyte.
