Give at least one example to explain the following properties.
(a) Sulphuric acid is a dibasic acid.
(b) Sulphuric acid is a dehydrating agent.
(c) Sulphuric acid is an oxidising agent.

Explanation

(a) `H_2SO_4` forms series of salts, i.e., both the hydrogen atoms are replaceable.
`H_2 SO_4 hArr H^(oplus) + HSO_4^(Ө) hArr 2 H^(oplus) + SO_4^(2-)`
`H_2 SO_4 + NaOH rarr underset("Sodium hydrogen sulphate(acid salt)")(NaHSO_4 + H_2 O)`
`H_2 SO_4 + 2NaOH rarr underset ("Sodium sulphate (Normal salt)")(Na_2 SO_4 + 2 H_2 O)`.
(b) `H_2 SO_4` has great affinity for water molecules and hence, acts as a dehydrating agent.
`HC COH overset (Conc.H_2 SO_4)rarr H_2 O + CO`.
(c) `H_2 SO_4` oxidises metals, non-metals and other compounds.
`Cu + 2H_2 SO_4 (conc.) rarr Cu SO_4 + SO_2 + 2H_2 O`
`S + 2H_2 SO_4 rarr 3SO_2 + 2H_2 O`
`2 HI + H_2 SO_4 rarr I_2 + SO_2 + 2H_2O`.