Doubling Celsius temp also double the pressure?

[Kaxa2000]

Does doubling the Celsius temp of a container also double the pressure?

I know it's true for Kelvin but I'm not sure about Celsius.

 

[mgb_phys]

No
Just trying a couple of values should convince you.

And in you system what would happen to the pressure if you went from 0C to 1C?

 

[Kaxa2000]

Which equation do I use to figure out if celsius doubles?

(T2/T1) = (P2/P1)

Do I use that?

 

[mgb_phys]

Almost, P1/T1=P2/T2=constant.

But a moments thought about what is double 0C should be enough.

You should also consider if changing the temperature by the same amount measured in C or F should have the same effect on pressure ?
Suppose you heat something from body temperature to the boiling point of water.
In C that's 37 -> 100 = 2.7x
In F that's 97 -> 212 = 2.2x

How does the gas molecules know what units you are using ?

 

[Kaxa2000]

I still don't understand your explanation mgb

 

[mgb_phys]

The law is that pressure/temperature is constant, doubling temperature doubles pressure.
I am trying to prove that this only works if you have an absolute 'temperature' ie. one that goes linearly from zero.

If you have a temperature that doesn't start from absolute zero you get some ridiculous answer, such as increasing the temp from freezing (0C) to 1C would mean an infinite increase in pressure.
And raising the temperature from body heat to boiling would give a different pressure change depending on what units you used.
Since these are impossible - it must be that you have to use absolute temperautre.

 

[Kaxa2000]

Ok thanks mgb...it makes more sense now...but couldn't you also have 0 Kelvin?? So wouldn't an increase from 0K to 1K do the same thing ?

 

[ideasrule]

Good point. The solution to the paradox is that we don't normally talk about gases at 1K; most (all?) gases liquefy above that temperature, and the ideal gas law doesn't apply anyways to gases at very low temperatures.

Think about what happens when a gas, say air, goes from 1 degree Celsius to 2 degrees Celsius. (This is hot enough that the ideal gas law applies, so we're safe in using this thought experiment.) Celsius temperature doubles, but the room in your air doesn't suddenly double in volume when the temperature goes from 1 degree Celsius to 2.

 

[Kaxa2000]

So we usually talk about Kelvin at around 273K and above which prevents using 0K. Isn't the Kelvin scale directly related to pressure since 0K = 0Pressure? but at zero pressure the celsius scale has a negative value.

 

[mgb_phys]

Yes that's the whole point of the kelvin scale.
From 0C to 1C is 274/273 = 0.3% increase in pressure.