Asample 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).

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

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 



V = 58.41 L
Volume at STP is 58.41 L

2.00 is the !