# Solution: A mixture of He and O2 is placed in a 4 L flask at 300 K. Th...

###### Question

A mixture of He and O2 is placed in a 4 L flask at 300 K. The partial pressure of the He is 2.7 atm and the partial pressure of the O2 is 1.4 atm. What is the mole fraction of O 2?

a. 0.341

b. 0.481

c. 0.518

d. 0.659

e. 0.224