Question

A gaseous mixture consists of 1.02 mol of helium, 0.36 mol of neon, and 1.58 mol of argon.

What is the mole fraction of helium in the mixture?

Answer 1

no of moles of He (nHe ) = 1.02 moles

no of moles of Ne (n Ne)   = 0.36 moles

no of moles of Ar ( n Ar)   = 1.58 moles

total no of moles   = n He + n Ne + n Ar = 1.02 + 0.36 + 1.58   = 2.96

mole fraction of He    X He   = n He/n He + n Ne + n Ar

                                              = 1.02/1.02 + 0.36+1.58    = 1.02/2.96    = 0.345   >>>>answer