Question

How is an `"unsaturated solution"` defined?

Answer 1

Hmm, have to word this with care. How about, " a solution that contains less than an equilibrium quantity of solute" ?

Explanation:

The definition of a `"saturated solution"` is...........

`"a solution that contains a concentration of solute equal"` `"to that concentration that would be in equilibrium with"`
`"undissolved solute"`.

Definitions such as the the solvent holds all the solute that it can are inadequate and incorrect.

So another attempt:

`"An unsaturated solution is a solution which contains an amount"` `"of solute LESS than the amount of solute that would be"` `"equilibrium with undissolved solute".`

So again our definition of `"saturation"` refers to an equilibrium property.