Which of these aqueous solutions is a strong electrolyte: H2CO3 , HClO2, HNO3, HC2H3O2
The correct answer and explanation is:
Correct Answer: HNO₃
Explanation:
To determine which of these aqueous solutions is a strong electrolyte, it is essential to understand what the term “strong electrolyte” means. A strong electrolyte is a compound that completely dissociates into ions in aqueous solution, allowing it to conduct electricity very effectively. These are typically strong acids, strong bases, or soluble salts.
Let’s evaluate each substance:
- H₂CO₃ (Carbonic acid):
This is a weak acid. It only partially dissociates in water into H⁺ and HCO₃⁻ ions. Because of its incomplete ionization, it does not produce enough ions to be a strong conductor of electricity. Therefore, it is a weak electrolyte. - HClO₂ (Chlorous acid):
This is also a weak acid. Like carbonic acid, it does not fully dissociate in solution. Only a portion of the HClO₂ molecules ionize to form H⁺ and ClO₂⁻. Hence, it is a weak electrolyte. - HNO₃ (Nitric acid):
This is a strong acid. It completely dissociates in water into H⁺ and NO₃⁻ ions. Because of its complete ionization, HNO₃ produces a high concentration of ions in solution, making it a strong electrolyte. It conducts electricity efficiently and is a textbook example of a strong acid and strong electrolyte. - HC₂H₃O₂ (Acetic acid):
This is a weak acid. In water, only a small fraction of acetic acid molecules dissociate into H⁺ and C₂H₃O₂⁻ ions. Most remain undissociated. Therefore, acetic acid is a weak electrolyte.
In conclusion, among the listed substances, only nitric acid (HNO₃) is a strong electrolyte because it completely dissociates in water, producing a solution rich in mobile ions that conduct electricity well.