Question

You have 10 lb of CO2 in a 20 ft3
fire extinguisher at 30 o
C. Assuming the ideal gas
law holds, what will be the gauge pressure (psig) on the tank when full?

Answer 1

Use PV=nRT equation
P= Pressure in Nm^-2
V= volume in cubic meters ( So we have to convert it )
n= No. of moles
R= universal gas constant
T= temperature in Kelvin. ( Since we are given it with Celsius We have to convert that )

Since we aren't given with the no. of moles.
We can find no. of moles by mass of CO2 divided by molar mass of CO2
But substitute mass of CO2 should be substituted in grams. SO u have to convert it.

Answer 2

I have used this but my answer is 64.39 psig but the correct answer should be 51.3 psig :( @Rushwr

Answer 3

oh wait here the unit we have to use is psig right?
ah then we have to convert the temperature to kelvin and Volume to cubic meters only !

Answer 4

i have converted ft3 to L and i have also used 0.0821 L atm/K mol for R