Question

Sodium hydroxide is a:
(A) A base
(B) An acid
(C) An alkali
(D) Both base as well as alkali

Answer 1

Hint: Sodium Hydroxide belongs to the inorganic compound category and is typically found at room temperature in the form of a white solid. Sodium cations and hydroxide anions consist of this chemical compound. The chemical formula of sodium hydroxide is listed as $ NaOH $ . Sodium Hydroxide is also popularly referred to as caustic soda. Bases are compounds which can release hydroxide ions.

Complete step by step solution
When sodium hydroxide is dissolved with water, it reacts to form a $ 50% $ saturation solution. Sodium hydroxide is a base and upon reaction with water, it dissociates into $ N{{a}^{+}} $ and $ O{{H}^{-}} $ ions.
This is the following reaction of sodium hydroxide with water:
 $ NaOH(s)+{{H}_{2}}O\to N{{a}^{+}}(aq)+O{{H}^{-}}(aq) $
We can observe that $ O{{H}^{-}} $ ion is produced during the reaction. This tells us that sodium hydroxide is basic in nature.
So, sodium hydroxide is a base.
The $ pH $ value of sodium hydroxide is $ 12 $ . It is one of the most powerful alkali because it releases $ O{{H}^{-}} $ in a very large amount. The degree of dissociation is also much greater in the $ NaOH $ solution. This tells us it is an alkali.
So, sodium hydroxide is also an alkali.
Hence, sodium hydroxide is both base as well as an alkali.
The correct option is (D.)

Additional Information
In the manufacture of soaps and a variety of detergents used in homes and business applications, sodium hydroxide is used. Chlorine bleach is manufactured by combining chlorine and sodium hydroxide.

Note
Sodium hydroxide is a highly caustic base and alkali that, at ordinary ambient temperatures, decomposes proteins and can cause serious chemical burns. It is highly soluble in water and absorbs humidity and carbon dioxide readily from the air.