Question

Which is the strongest base?
A. NaOH
B. $Mg{{(OH)}_{2}}$
C. $N{{H}_{4}}OH$
D. None of these

Answer 1

Strong bases are the compounds that liberate huge amounts of $O{{H}^{-}}$ ions in aqueous solution. Weak bases are the compounds which do not ionize completely but liberate a few $O{{H}^{-}}$ ions in aqueous solution.

Complete answer:
- In the question it is asked to find the strong base among the given options.
- We know that a strong base is the chemical substance which liberates large amounts of $O{{H}^{-}}$ ions in aqueous solution.
- Coming to the given options. Option A, NaOH.
- When NaOH is added to aqueous solution we will observe the following chemical reaction.
$NaOH\to N{{a}^{+}}+O{{H}^{-}}$
- Sodium hydroxide will dissociate completely when added to water then it is a strong base.
- Coming to option B, $Mg{{(OH)}_{2}}$ . Magnesium hydroxide is an insoluble complex and not soluble in water completely. Then it is a weak base.
- Coming to option C, $N{{H}_{4}}OH$ . Ammonium hydroxide is an insoluble complex and not soluble in water completely. Then it is a weak base.
- Coming to option D, none of the above. It won’t suit the question.
- Therefore Sodium hydroxide is a strong base.

So, the correct option is A.

Note:
Weak bases have a pH range in between 8 – 10, while coming to strong bases the pH ranges between 10 - 14. Basic compounds are also called alkali compounds. Ionization of compounds is very important to know about the acidity or basicity of the compounds.