Gas solution - State of matter
Good question! For a solid dissolved in liquid, obviously the solid behaves as a liquid rather than as a solid, since its particles are separated and moving freely. 

A gas, though, is defined as free to fill its container, unlike a liquid with a definite volume. Since a dissolved gas (as opposed to one chemically bound to a liquid) is free to disperse, e.g. $\ce{CO2}$ bubbling out of seltzer, one might still consider it gaseous, rather than liquid, just loosely bound to the liquid.

That said, in a closed container in equilibrium, or over a short time, dissolved gases do behave as liquids. One can pour $\ce{NH4OH}$ ($\ce{NH3}$ aq.) into $\ce{H2SO4}$ ( $\ce{SO3}$ aq.), and the majority of the dissolved gases stay in solution -- though some $\ce{NH3}$ gets out, leaving one tearing and coughing, if not done under a hood.

It appears to be a matter of definition, then if dissolved gases are considered as gas or liquid.

BTW, gases dissolved in solids, such as methane clathrate, are more tightly locked in place and may behave as solids until warmed.