Question

The $K_a$ value of ammonium ion $\left(NH{{}_4}^{+}\right)$ is $5.6\times {10}^{-10}$, the $K_b$ value of ammonia $N{H}_3=1.8\times {10}^{-5}$,then :

• A. Ammonia is more strongly basic than ammonium is acidic.
• B. Ammonia is weaker basic than ammonium is acidic.
• C. Both a and b
• D. Data insufficient

Answer 1

The correct option is A Ammonia is more strongly basic than ammonium is acidic.

The relative strength of an acid or base depends on how high its $k_a$ or $k_b$ value is, in this case, the$k_a$ value is far lower than the $k_b$ value, so the ammonia is more strongly basic than ammonium is acidic.