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Thu 7 Apr, 2005 10:18 am
How would I do this? At STP, one mole of any gas is 22.4 liters. I suppose I'd have to find a new number of liters per mole at the new conditions, but I don't know how.
If you have 11.5 liters of O2 at 2.66 atm and 298 K, how do you express that in moles?
PV=nRT
rearranged to
n=PV/RT
P is pressure
V is Volume
R is the Gas constant
T is absolute temperature
STP consitions
P=1 atm
T=25DegC (273+25=298Deg K-absolute temperature)
V=22.4l/g-mole
In your case
V=1/2.66*22.4 liters/gmole
Rap
Good Basic Start
Depending on your class, that will work, or your prof will want you to use a more advanced equation. O2 is not an ideal gas, but using the ideal gas law will show you understand the principles involved. If you have studied other forms of the gas equation, you might be expected to look up the appropriate constants for O2 and use one of them.
Somehow I doubt that any of the alternate gas laws other than the ideal gas law are being considered. Besides at room temperature and less than 40 psia even oxygen is ideal to two significant digits.
As a practicing Engineer would usually say---that's good enough.
Rap
Ouch!
Ouch! Ouch! But we know that classroom conditions to not reflect reality.
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