# why is humid air an example of liquid gas solution instead of gas gas solution? [closed]

In my textbook, humid air is given as an example to liquid in gas solution. But isn't humidity the amount of water vapour (gas) and therefore should be gas in gas solution?

• A solution is a single phase by definition. So as soon as there is liquid water (droplets) in air, it is not a solution. May 7 at 9:04
• A asking B why C has written something wrong will not provide the answer unless B knows the history or context of such writing. May 7 at 11:15
• Would be nice if you post the identity of the source textbook. May 9 at 11:05

The equilibrium concentration of water in the atmosphere depends on temperature. It is almost independent of the amount of air (or other gases) that is present and therefore it is almost independent of the total ambient pressure. A vacuum has approximately the same equilibrium concentration of water vapour as the same volume filled with air. At $$10\ \mathrm{^\circ C}$$, it is about $$9.4\ \mathrm{g/m^3}$$, at $$20\ \mathrm{^\circ C}$$, it is about $$17.3\ \mathrm{g/m^3}$$, and at $$30\ \mathrm{^\circ C}$$, it is about $$30.4\ \mathrm{g/m^3}$$.