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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: mana on December 25, 2021, 11:57:51 AM

Title: changing temperature of an ideal gas by changing volume?!
Post by: mana on December 25, 2021, 11:57:51 AM
hi all
as you know Charles's rule says " the volume of an ideal gas is directly proportioned with temperature (kelvin)" now my question is if I reduce the volume of an ideal gas, does the temperature decrease too?
thanks in advance for your help
Title: Re: changing temperature of an ideal gas by changing volume?!
Post by: Hunter2 on December 25, 2021, 12:14:01 PM
The key is the ideal Gas law.
pV = nRT
So you can play with all parameters. Temperature can decrease but can also be constant if you change pressure for example.
Title: Re: changing temperature of an ideal gas by changing volume?!
Post by: mana on December 25, 2021, 12:24:40 PM
The key is the ideal Gas law.
pV = nRT
So you can play with all parameters. Temperature can decrease but can also be constant if you change pressure for example.
Thus it will decrease or it is constant? honestly, it is very strange to me that by decreasing the volume of an ideal gas, the temperature decreases too, I mean I can't imagine that, but the Charles rule says it must happen???
Title: Re: changing temperature of an ideal gas by changing volume?!
Post by: Hunter2 on December 25, 2021, 01:11:28 PM
It's simple mathematics. If volume decrease at half and pressure and moles keep constant then temperature decrease at half as well the same if temperature is constant  the pressure has to be the double amount.
Title: Re: changing temperature of an ideal gas by changing volume?!
Post by: billnotgatez on December 25, 2021, 05:02:07 PM
@mana

If you have a balloon filled with dry air and the temperature goes from 90F to 0F do you expect the balloon to expand or contract (assuming barometric pressure stays constant)?