Question

The preferred IUPAC name of Caustic soda is:
(A) sodium bicarbonate
(B) sodium carbonate
(C) sodium hydroxide
(D) sodium sulphate

Answer 1

Hint: The IUPAC name of caustic soda can be figured out from the chemical formula of the compound. Caustic soda is a very strong base.

Complete step by step answer:

The chemical formula of Caustic Soda is NaOH. This signifies that there is the presence of -OH group in the compound. We all know that the OH group is known as the hydroxide group.
The IUPAC name of Caustic Soda can be called Sodium Hydroxide.
Therefore, the correct answer to the question is Option C.
In option A, we can see the compound that is mentioned is Sodium Bicarbonate. The commercial name of the compound is Baking Soda. So, this cannot be the correct answer. The formula of the compound is $\text{NaHC}{{\text{O}}_{\text{3}}}$.
In option B, we can see the mentioned compound is Sodium Carbonate. The commercial name of Sodium Carbonate is Washing Soda. The formula of the compound is $\text{N}{{\text{a}}_{\text{2}}}\text{C}{{\text{O}}_{\text{3}}}$. So, this cannot be the correct answer.
In option D, we can see it is mentioned as Sodium Sulphate. The formula of the compound is $\text{N}{{\text{a}}_{\text{2}}}\text{S}{{\text{O}}_{\text{4}}}$. The commercial name of the compound is a sulphate of soda. So, this cannot be the correct answer.
Sodium Hydroxide is an alkali which is called Caustic Soda. By Caustic we mean burning.
- Caustic Soda takes away the name by the way it burns the skin. As a solid the alkali is deliquescent and readily absorbs moisture and carbon dioxide from the air.
- Sodium Hydroxide is a strong base because it fully dissociates in water to produce the hydroxide ions.

Additional Information: Sodium Hydroxide is a versatile alkali. It is used in the manufacture of pulp and paper, alumina, soaps and other chemical productions. The best way to neutralize Sodium Hydroxide in case of skin exposure is by treating it with boric acid solution or ammonium chloride solution.

Note: The typical method to determine the strength of Sodium Hydroxide is by titration. In this method, a sample of Sodium Hydroxide is treated with a strong acid like hydrochloric acid, or sulphuric acid. Phenolphthalein is used as an indicator.