If a total of 17.7 mol of gas is present, what amount (in moles) of Ne is present?

Question

A gas mixture contains the noble gases Xe, Kr, and Ne. The total pressure of the mixture is 5.17 atm, and the partial pressure of Ne is 2.87 atm. If a total of 17.7 mol of gas is present, what amount (in moles) of Ne is present?

______ mol Ne

Answer 1

Partial pressure of gas in a mixture is equal to mole fraction times total pressure. So mole fraction of neon is

P_Ne/ P_total = 2.87 atm/5.17 atm = 0.5541

Number of moles of neon = mole fraction of neon multiplied by total number of moles

0.5541 x 17.7 moles = 9.81 moles of neon