iii. Why NaOH
is a strong but NH4OH
is a weak electrolyte? Ans: The answer of the given question is explained under the following
The Correct Answer and Explanation is:
Why NaOH is a Strong but NH₄OH is a Weak Electrolyte
Answer:
Sodium hydroxide (NaOH) is classified as a strong electrolyte because it completely dissociates into ions in aqueous solution, while ammonium hydroxide (NH₄OH) is a weak electrolyte because it only partially dissociates in water.
Explanation:
Electrolytes are substances that, when dissolved in water, produce ions that can conduct electricity. The strength of an electrolyte depends on the extent to which it ionizes in water.
1. Sodium Hydroxide (NaOH): Strong Electrolyte
Sodium hydroxide is an ionic compound composed of Na⁺ (sodium ion) and OH⁻ (hydroxide ion). When NaOH is added to water, it completely dissociates into its constituent ions:NaOH (aq)→Na⁺ (aq)+OH⁻ (aq)\text{NaOH (aq)} \rightarrow \text{Na⁺ (aq)} + \text{OH⁻ (aq)}NaOH (aq)→Na⁺ (aq)+OH⁻ (aq)
This complete dissociation means that all the NaOH molecules break apart into ions, providing a high concentration of charge carriers in the solution. As a result, NaOH solutions conduct electricity very efficiently, which characterizes it as a strong electrolyte.
2. Ammonium Hydroxide (NH₄OH): Weak Electrolyte
Ammonium hydroxide is a weak base and exists in equilibrium with ammonia (NH₃) and water. It partially ionizes in aqueous solution:NH₄OH (aq)⇌NH₄⁺ (aq)+OH⁻ (aq)\text{NH₄OH (aq)} \rightleftharpoons \text{NH₄⁺ (aq)} + \text{OH⁻ (aq)}NH₄OH (aq)⇌NH₄⁺ (aq)+OH⁻ (aq)
This reaction is reversible, and only a small fraction of NH₄OH molecules actually produce ions. The majority of the compound remains as undissociated NH₄OH molecules in the solution. Because of this incomplete ionization, the number of ions available to conduct electricity is low, making NH₄OH a weak electrolyte.
Conclusion:
The key difference lies in the degree of ionization. NaOH, being an ionic compound, dissociates fully in water and thus behaves as a strong electrolyte. NH₄OH, on the other hand, ionizes only partially due to its weak base nature, making it a weak electrolyte.
