Question

A sample of Freon-12 (CF2Cl2) occupies 2.842 x 101 L at 331 K and 2.525 x 102 kPa. Find its volume (in L) at standard temperature and pressure (STP).

Answer 1

we have to first find the number of moles of Freon-12 in the sample using the ideal gas law equation
PV = nRT
n =
`(PV)/(RT)`
since the number of moles at both conditions given and at stp we can write the following formula

`(P1V1)/(RT1) = (P2V2)/(RT2)`
where parameters for the given conditions are on the left side and parameters for STP conditions are on the right side of the equation
where P1 - pressure - 252.5 kPa
V1 - volume - 28.42 x 10⁻³ m³
R - universal gas constant
T1 - 331 K

STP conditions
P2 - 101 325 Pa
T2 - 273 K

substituting these values in the equation


`(252 500Pa*28.42*10 ^(-3)m^(3) )/(R*331K) = (101325 Pa*V)/(R*273 K)`

V = 58.41 L
Volume at STP is 58.41 L