It combines all the three parameters of temperature, pressure and volume.
(P1 V1) /T1= (P2 V2)/T2
Also, Pv = nRT
Where n = number of moles, (R = 0.082 atom dm3 k-1 mol-1).
Example 1
If a gas exerts a pressure of 10N/m2 to occupy a volume of 40m3 at 127°C, what will be the volume occupied by pressure of 20N/m2 at 27oc.
Solution
(P1 V1) /T1= (P2 V2)/T2
P1 = 10N/m2, V1 = 40m3, T1 = 127°c =273o =400°K
T2 = 27 + 273 = 300oK, P2 = 20N/m2
V2 = (P1 V1 T2)/(p2T1)
= (10 x 40 x 30) / (20 x 400)
= 15m3
Example 2
A certain amount of gas occupies 10. 0dm3 at 2 atm and 10oc, Find the number of moles present. (R = 0.082atm dm3 K-1 mol1).
Solution
PV = nRT
n = PV/RT
P = 2 atm, V = 10dm3
10°C = 10 + 273 = 283°K
n = (2 x 10)/(0.082 x 263)
= 0.0862 moles