Question

Acidity of ammonium hydroxide is _______
(A) 1
(B) 2
(C) 4
(D) 3

Answer 1

Ammonium hydroxide is a monoacidic base. Actually, acidity and basicity of any compound goes hand in hand.

Complete step by step solution:
Ammonia in water results in ammonium hydroxide. $N{{H}_{4}}OH$ is often denoted as $N{{H}_{3}}\left( aq \right)$.$N{{H}_{4}}OH$ is a base and it dissociates to give a hydroxide ion to define its basicity.
$N{{H}_{4}}OH\rightleftharpoons N{{H}_{4}}^{+}+O{{H}^{-}}$
Acidity-
It is an extent to which a substance will donate a proton or hydrogen ion.
Basicity-
It is an extent to which a substance will accept a proton or hydrogen ion.
Thus, the acidity of a compound which is a base basically can be defined as;
The affinity of basic anion to combine with a cation to form stable compounds is known as acidity of that compound as well.
Also, the number of ionizable hydroxide ions present in a molecule of base is called the acidity of bases.
So, $N{{H}_{4}}OH$ is a monoacidic base which means that it has one hydroxide ion per molecule. This one ion is replaceable and dissociates in one step. The only one hydroxide can be combined to positive ions which would result in stability and will define its acidity as well.
Thus, the acidity of $N{{H}_{4}}OH$ is one.

Therefore, option (A) is correct.

Note: Do remember that acidity and basicity are based on the same reaction taking place just the ways of looking towards them is different.
Simply, we can say that acidity depends upon the presence of $O{{H}^{-}}$ions present in the solution or compound and basicity depends upon the presence of ${{H}^{+}}$ ions in the solution or compound.