What is the partial pressure (in mm Hg) of neon in a 4.00 L vessel that contains 0.442 mol of methane, 0.414 mol of ethane, and 0.859 mol of neon at a total pressure of 943 mm Hg?

Answer 1

Use mole fraction.
mole fraction Ne = moles Ne/total moles.
partial pressure Ne = mole fraction Ne x total P.