Question

explain why concentrated sulphuric acid becomes dilute when exposed to air

Answer 1

Generally 98% Sulphuric acid is called as concentrated sulphuric acid. Sulphuric acid is highly hygroscopic i.e it will attract water molecules immediately from its vicinity. If kept open then it will absorb moisture from atmosphere and its concentration will change and it may no longer have the exact acid to water ratio. Second reason is for safety. As concentrated H2SO4 is highly corrosive, if it spills over then the damage might be irreparable. Third reason is vaporisation. Sulphuric Acid is not very volatile but still keeping it open can lead to loss of fumes. For all the above reasons, concentrated sulphuric acid is stored in airtight bottles.

Answer 2

answer:

when conc sulphuric acid exposed to air it absorb moisture from air because it is a dehydrating agent and when water is taken by it the concentration of it reduces and forms diluted