[alex626]

I dont understand how to work with this problem....Can someone please help and explain so I can understand...please
Alexandria
 i know that pressure is what I am looking for...Pressure=force/area-----what is the force in this equation and what is the area?
 
A gas cylinder contains 2.50 x 103 grams of O2 gas in a volume of 10.0 liters. What pressure
is exerted by the oxygen at 20.0 oC?

[ifuller]

It is true that P = f/A. However, I think there is an equation that can take into account more of your variables. It is an expansion of the ideal gas law (pv=nrt). It states

pvm=grt.

Where p is the pressure in atmospheres
v is volume in liters
m is the molar mass of the gas given
g is the number of grams of that gas
r is the ideal gas constant (.0821)
and t is the temperature in Kelvin.

Check out http://en.wikipedia.org/wiki/Ideal_gas_law if you want more information. Hope this helps