Question

Sulphuric acid \[({H_2}S{O_4})\] has the following uses.
i. Concentrated \[{H_2}S{O_4}\] ​ is a drying agent.
ii. \[{H_2}S{O_4}\]​ is used to prepare nitric acid in the laboratory.
Illustrate the uses with suitable examples.

Answer 1

Hint: We must have observed in the laboratory that \[{H_2}S{O_4}\] immediately dries up the substance on which it spills and we can observe fumes or vapors also. This means H2​SO4 dries up the substance.

Complete step by step solution:
Case 1:
We must know that a substance that absorbs moisture from its surroundings is called the Drying agent. Sulfuric acid$({H_2}S{O_4})$ readily reacts with\[{H_{2}}O\]. Reaction of \[{H_2}S{O_4}\] with water leads to the formation of hydronium ion$({H_3}{O^ + })$. So, \[{H_2}S{O_4}\]is known as a good drying agent.
\[{H_2}S{O_4}\] is a hygroscopic substance used as a drying agent and also as a dehydrating agent. \[{H_2}S{O_4}\] has a great affinity for water. It immediately removes water molecules from other compounds without dissolving it. so it is considered a good desiccation or drying agent.
We must know that the concentrated \[{H_2}S{O_4}\]​ is used for drying some gases like sulfur dioxide (SO2​) and hydrogen chloride (HCl) during their laboratory preparation.
Therefore, we can conclude that the concentrated \[{H_2}S{O_4}\]​ can be used as a drying agent.
Case 2:
 We can prepare nitric acid from sulphuric acid by the Ostwald process in the laboratory. Therefore, concentrated \[{H_2}S{O_4}\] reacts with sodium nitrate$(NaN{O_3})$ to produce nitric acid$(HN{O_3})$ as follows
\[NaNO3 + H2SO4 \to NaHSO4 + HNO3\]
Hence, this reaction is used to prepare nitric acid in the laboratory.

Note: When we react with sulphuric acid with sugar molecules it becomes charring. because of dehydration of carbon(C) and hydrogen(H) of sugar molecules. This is an important characteristic reaction for analysis of sugar molecule.and also we must know that only concentrated \[{H_2}S{O_4}\] acts as a good dehydrating agent. Dilute \[{H_2}S{O_4}\] does not act as a drying agent because dilute sulphuric acid itself contains water and will not be able to absorb water from other substances.