Question

Explain clearly how conc. $H_{2}S{O}_4$ is used as dehydrating as well as drying agent.

Answer 1

Sulphuric acid is used as drying agent and dehydrating agent because Sulphuric acid has a great affinity for water. It readily removes elements of water from other compounds i.e, it acts as a dehydrating agent, it being a hygroscopic substance absorb water from other substances without dissolving in it,so it is considered a good drying agent. But remember , that only concentrated sulphuric acid is a good dehydrating agent not dilute acid because dilute sulphuric acid itself contains water and will not be able to absorb water from other substances.