Question

Is sulphurous acid a volatile or non-volatile,give reason?

Answer 1

Sulfurous acid is volatile.

Explanation:

"Sulfurous acid" is a solution of `"SO"_2` in water.

There is no evidence that `"H"_2"SO"_3` molecules exist in an aqueous solution.

Instead, there is an equilibrium

`"SO"_2 + 2"H"_2"O" ⇌ "H"_3"O"^"+" + "HSO"_3^"-"`

However, water has a vapour pressure, so the solution is volatile.

It is not possible to say whether or not `"H"_2"SO"_3` is volatile because all attempts to isolate it by removing the water produce `"SO"_2`.

That is, the equilibrium goes in reverse.