First of all, let's find the number of moles of the gas.
The molar mass of argon is
![M_m=40 g/mol=0.40 kg/mol](https://img.qammunity.org/2019/formulas/physics/college/jp4gmv33txnsbnvhecemkbgo1mbo788gqm.png)
. Since we have
![m=23.3 kg](https://img.qammunity.org/2019/formulas/physics/college/68tlnxfhdlukgyg4rziudhp63zbotxw1ab.png)
of gas, the number of moles is
![n= (m)/(M_m)= (23.3 kg)/(0.40 kg/mol)=58.3 mol](https://img.qammunity.org/2019/formulas/physics/college/qqlv8ouue91jaun59t1jl3podzchqqxqx1.png)
Now we can use the ideal gas law to calculate the pressure of the gas:
![pV=nRT](https://img.qammunity.org/2019/formulas/physics/college/lu0krl61tfdxfxo8ojxqzcbfgy589vl1g7.png)
where
p is the pressure
![V=212 L=0.212 m^3](https://img.qammunity.org/2019/formulas/physics/college/fq63guy2tw902nnc8ksboijy9h7demnh7x.png)
is the volume
![n=58.3 mol](https://img.qammunity.org/2019/formulas/physics/college/h7cqp9q40nst6iud6ooar77s2s9h48qfhz.png)
is the number of moles
![R=8.31 J/mol K](https://img.qammunity.org/2019/formulas/physics/college/56z5v7glt7htf2906zv6f32tefitxxaiof.png)
is the gas constant
![T=25^(\circ)+273=298 K](https://img.qammunity.org/2019/formulas/physics/college/86as31bzw1l5yo1qfrkpwozbybpfzgi2k0.png)
is the absolute temperature
Rearranging the equation, we find
![p= (nRT)/(V)= ((58.3 mol)(8.31 J/mol K)(298 K))/(0.212 m^3)=6.81 \cdot 10^5 Pa](https://img.qammunity.org/2019/formulas/physics/college/mkwzr6wv4o2a4unitzvwfots2dlc4isx5w.png)