Could someone please help guide me through this question:

Question

A 1.047 g sample of He(g) is found to occupy a volume of 8.446 L when collected over hexane at 25.0 ∘C and 739.6 mmHg barometric pressure. Use these data to determine the vapor pressure of hexane at 25 ∘C.

Answer 1

Use 1.047 g to calculate mols He. mols = grams/atomic mass.

Then use PV = nRT and solve for P. This will be in atm; I would conert that to mm Hg. atm x 760 = pHe in mmHg.

Then Ptotal = pHe + phexane
You know Ptotal = 739.6 mm
You know PHe from PV = nRT; solve for phexane.