Gas pressure and temperature relation

In summary, when a gas is compressed, the molecules are forced closer together and have a higher probability of colliding with each other, resulting in a transfer of kinetic energy and an increase in temperature. This increase in temperature is proportional to the average kinetic energy of the particles and the pressure exerted by the molecules on the container walls. This explains why compressed gases heat up. As for why compressed gases turn cold when they become liquids, it is due to the change in state and the specific properties of each substance. Friction does not play a role in this process.
  • #1
dusty8683
22
0
just trying to understand how/why these two are proportional. if you compress a gas all the atoms and/or molecules would have less room to move around. so does the friction between these moving objects create heat? and if when gasses are compressed they heat up... why then when they are compressed to a liquid are they extremely cold? any explanation would be helpful, even just a link that has an explanation would do. thanks
 
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  • #2
dusty8683 said:
just trying to understand how/why these two are proportional. if you compress a gas all the atoms and/or molecules would have less room to move around. so does the friction between these moving objects create heat?

The temperature has nothing to do with friction, but just with colliding effects. The more pressure the less space between molecules, and then major probability of colliding each other, and then the more kinetic energy transferring, and then the more average kinetic energy, and then the more temperature, and then... :zzz:
 
  • #3
The larger the temperature of a gas the faster the molecules will move (temperature is proportional to the average kinetic energy of the particles) and the larger the force they will excert, and the higher the pressure (pressure is the force excerted by the particles divided by the area).
 
  • #4
See also https://www.physicsforums.com/showthread.php?t=39446

My answer there was:
Microscopically the force on a container wall with some (ideal) gas in it is proportional to the average velocity (determines the rate of collisions) and momentum (determines the 'impact' of the collisions) of the molecules constituting the gas.

As you might know, pressure is a force per area. Kinetic energy is half the product of momentum and velocity. So you can easily see that pressure is proportional to the average kinetic energy and thus the temperature...
 

1. How does temperature affect gas pressure?

According to the ideal gas law, there is an inverse relationship between temperature and gas pressure. This means that as temperature increases, gas pressure decreases and vice versa. This is because as temperature increases, the molecules of gas have more energy and move faster, resulting in more collisions with the walls of the container. This increases the pressure exerted by the gas.

2. What is the mathematical relationship between gas pressure and temperature?

The mathematical relationship between gas pressure and temperature is described by the ideal gas law, which states that pressure is directly proportional to temperature (when volume and number of moles are constant). This can be represented by the equation: P ∝ T or P = kT, where P is pressure, T is temperature, and k is a constant.

3. How does high pressure affect gas temperature?

High pressure has a direct effect on gas temperature, causing it to increase. This is because at high pressures, gas molecules are packed closer together, resulting in more frequent collisions and an increase in kinetic energy. This increase in kinetic energy translates to an increase in temperature.

4. What is the relationship between gas pressure and volume?

According to Boyle's Law, there is an inverse relationship between gas pressure and volume (when temperature and number of moles are constant). This means that as pressure increases, volume decreases and vice versa. This is because as the volume of a gas decreases, the molecules are closer together, resulting in more collisions and an increase in pressure.

5. How does changing the number of gas molecules affect pressure and temperature?

Changing the number of gas molecules affects both pressure and temperature. In terms of pressure, increasing the number of gas molecules in a given volume will result in an increase in pressure. In terms of temperature, increasing the number of gas molecules will also increase temperature, as there are more molecules with kinetic energy, resulting in more collisions and an increase in temperature. This is described by the ideal gas law, where pressure and temperature are directly proportional to the number of moles of gas.

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