Assuming temperature and moles of gas remains the same, then decreasing the volume of the gas will increase the pressure. Decreasing the volume enough will result in non ideal behavior.
The molecules will not collide as often with the walls decreasing the volume
Decreasing the pressure applied to the gas (apex)
No, it does affect the volume of a gas according to the ideal gas law (PV=nRT).
a temperature which gas can not be liquified by applying pressue.
If the volume of the container is not fixed, increasing the temperature will cause a gas to expand (increase the volume), and contract when cooled (decreasing the volume). This would be the case for a gas inside a piston, or inside a rubber balloon. If the volume is fixed, then increasing the temperature will increase the pressure, and decreasing the temperature will decrease the pressure. This would be the case for a gas in a closed solid container, like a canister or sealed metal box. Increasing pressure will cause the gas to contract (reducing the volume), and decreasing the pressure will cause the gas to expand (increasing the volume). Again, this is if the volume is not fixed. If the volume is fixed, then increasing the pressure will increase the temperature, and decreasing the pressure will decrease the temperature. These concepts are all determined by something called the Ideal Gas Law. To find out more about how this works, see the Related Questions links below this answer. Gases can also be changed to a liquid or solid if the temperature is too low or the pressure is too high. As an example steam changes to a liquid when it touches a cold object, and nitrogen gas can be converted to liquid nitrogen by compressing it to very high pressures.
If the temperature remains constant, decreasing the volume will increase the pressure.
The pressure increase.
The molecules will not collide as often with the walls decreasing the volume
No, it will not.
As indicated by Charles's Law, at constant pressure, the volume decreases when the temperature decreases. This is due to slowed collisions between molecules.
Decreasing the pressure applied to the gas (apex)
decreasing the volume available for the gas or increasing its temperature
If the temperature of the gas is decreasing, then in order to maintain constant pressure, you would have to compress it in volume.
As the temperature of a gas increases, so does the volume.
Gas tends to take the shape of the volume it's in. If the volume is reduced, then the pressure of the gas will increase.
It affects pressure, not volume.
No, it does affect the volume of a gas according to the ideal gas law (PV=nRT).