Pressure pushes a gas in
Temperature is one factor for a gas. There is a second, and an unopened bottle will demonstrate it.
Activity 3.1.10 — method
Get an unopened plastic bottle of soda from a shop. Take an empty bottle of the same kind and put into it a volume of water equal to the volume of soda in the first, then cap it tightly. Now squeeze both bottles in your hand and test which is the harder.
Figure to be added
The observation
The unopened soda bottle is so hard you cannot squeeze it. The bottle of water gives under your hand.
Why it is hard
Carbon dioxide has been forced into the space above the liquid in the soda bottle under high pressure. The moment the cap is opened that gas escapes, and the bottle loses its hardness.
Figure to be added
What that says about solubility
Raising the pressure of a gas in contact with a liquid raises how much of that gas dissolves in it. So the water solubility of a gas is decided by two factors:
1 — Temperature
Raise the temperature and less gas stays dissolved.
2 — Pressure
Raise the pressure of the gas above the liquid and more of it dissolves.
Both factors, in one bottle
A warm fizzy drink goes flat faster than a cold one, and an open bottle goes flat faster than a closed one. That is temperature and pressure working on the same dissolved gas at the same time.