Calculate the pressure of 1x10 to the power 22 molecules of oxygen gas when enclosed in a vessel of 5L capacity at temp of 27 degree Celcius.

(Ans=0.817 atm)

Help please!

Dear student!

We know that, 

 6.022 x 10²³ molecules of O₂ gas contains = 1 mole of O₂ gas 

Hence,  1x 10²² molecules of O₂ gas contains = (1/ 6.022 x 10²³ ) x10²² mole of O₂ gas = 0.0166 mole of O₂ gas 

Hence, n = 0.0166, T = 273 + 27 =  300 K ,V = 5L, R = 0.0821 L.atm/mol.K

So, we have,

PV = nRT

Or , P = nRT/V = 0.0166 x 0.0821 x 300/ 5 = 0.40887/5 =0.0817 atm