What will the be the partial pressure of He and O2 respectively if 200ml of He at 0.66 atm and 400ml of O2 at 0.52 atm pressure are mixed in 400ml vessel at 20°C

P V=nRTnHe==0.66×200RTnO2=0.52×400RTPV = nRTP=nHe+nO2RT400PT=0.66×200+400×0.52400∵XHe=nHenO2+nHeXHe=0.66×2000.66×200+400×0.52=132132+208PHe=XHePtotal=132340×340400⇒PHe=0.33XO2=208400 So, PO2=0.52orPO2= Ptotal - PHe = 0.85 - 0.33 = 0.52