The ideal gas law states that:
[tex]pV=nRT[/tex]
where
p is the gas pressure
V is its volume
n is the number of moles
R is the gas constant
T is the absolute temperature of the gas
For the gas in our problem:
[tex]p=25325 kPa = 2.53 \cdot 10^4 kPa = 2.53 \cdot 10^7 Pa[/tex]
[tex]V=12.5 L = 12.5 \cdot 10^{-3} m^3[/tex]
[tex]T=22^{\circ}C = 295 K[/tex]
If we plug the data into the equation, we can find the number of moles of the gas:
[tex]n= \frac{pV}{RT}= \frac{(2.53 \cdot 10^7 Pa)(12.5 \cdot 10^{-3} m^3)}{(8.31 J/mol K)(295 K)}=129 mol [/tex]
