Which one of the following is NOT a strong electrolyte?
A) LiOH
B) HNO3
C) KBr
D) NH CI
E) HNO
The Correct Answer and Explanation is :
The correct answer is D) NH₄Cl.
Explanation:
To understand why NH₄Cl is not a strong electrolyte, it is important to first know what a strong electrolyte is. A strong electrolyte is a substance that completely dissociates into ions when dissolved in water. These substances conduct electricity very efficiently because they produce a large number of ions in solution.
Let’s analyze each option:
- LiOH (Lithium hydroxide):
Lithium hydroxide is an ionic compound, and like other alkali metal hydroxides (e.g., NaOH, KOH), it dissociates completely in water. It forms Li⁺ and OH⁻ ions in solution, making it a strong electrolyte. - HNO₃ (Nitric acid):
Nitric acid is a strong acid, and strong acids completely dissociate into their ions when dissolved in water. In the case of HNO₃, it dissociates into H⁺ and NO₃⁻ ions, making it a strong electrolyte. - KBr (Potassium bromide):
Potassium bromide is an ionic compound. When it dissolves in water, it dissociates completely into K⁺ and Br⁻ ions, making it a strong electrolyte. - NH₄Cl (Ammonium chloride):
Ammonium chloride is an ionic compound that dissolves in water to form NH₄⁺ and Cl⁻ ions. While it dissociates into ions, the ammonium ion (NH₄⁺) is not as readily dissociated or as conductive as the ions from a strong base or acid. Therefore, NH₄Cl is considered a weak electrolyte because it does not dissociate as completely as the others listed. - HNO₃ (Nitric acid):
This is the same substance mentioned earlier in option B. As explained, it is a strong acid and a strong electrolyte because it dissociates completely in water.
In summary, NH₄Cl is the only compound listed that does not dissociate fully into ions in solution, making it a weak electrolyte compared to the others, which are all strong electrolytes.