First of all, let's find the number of moles of the gas.
The molar mass of argon is [tex]M_m=40 g/mol=0.40 kg/mol[/tex]. Since we have [tex]m=23.3 kg[/tex] of gas, the number of moles is
[tex]n= \frac{m}{M_m}= \frac{23.3 kg}{0.40 kg/mol}=58.3 mol [/tex]
Now we can use the ideal gas law to calculate the pressure of the gas:
[tex]pV=nRT[/tex]
where
p is the pressure
[tex]V=212 L=0.212 m^3[/tex] is the volume
[tex]n=58.3 mol[/tex] is the number of moles
[tex]R=8.31 J/mol K[/tex] is the gas constant
[tex]T=25^{\circ}+273=298 K[/tex] is the absolute temperature
Rearranging the equation, we find
[tex]p= \frac{nRT}{V}= \frac{(58.3 mol)(8.31 J/mol K)(298 K)}{0.212 m^3}=6.81 \cdot 10^5 Pa [/tex]
