Question

A mixture of oxygen and helium gases, in a 9.44 L flask at 61 °C, contains 7.69 grams of oxygen and 0.430 grams of helium. The partial pressure of helium in the flask is atm and the total pressure in the flask is atm. back is

Answer 1

An&Der mass Numbes of moles 11 molar mas2 Molas mass of He = 4 003 /mol 8/mot 32 O0 Molay mass of 02- 7.69 32 60 0.2463 moles of 02 moles of 02 . 7.69 3 of 02 O.430 moles of He = 0.1074 anoles of He O-430 of He 4.003 So total mum ber of moles of gases in mixture - (0-2403+0.10H) moles 0.3477 anoles Mole fraction of He in mixtureno.of molea of He Total no. 0f moies O-1071 moles O.3477 mole O.3089 1

Let's assume mixture of gasee behaves ideally .. Prixture Vinixture mixture R T Pis pressuye V is volume, n is number of mole s, R is gas conatant and T is tempesature in kelvin) Here 9 mixture - 0.3477 noles Vmixture 9.44 L T- (273+61)K = 334 K L-atm x (A-44L) (0-3477 ma)x-0321 x (334 k) PMixt ure mol/X Pmixtuse 1.01 atm total press ure in flask is 1.01 atm So (total Pressure) mole fractionX of He Partial Pre ssure of He = Co-3081)X (1-01 atm) 0.312 atm