A 12 g sample of Ne is added to a container that also holds .78 mol of helium gas. What is the partial pressure of helium if the total pressure, after mixing is 2.43 atm?

Question

A 12 g sample of Ne is added to a container that also holds .78 mol of helium gas.  What is the partial pressure of helium if the total pressure, after mixing is 2.43 atm?

DrBob222 · Answer

mol He = 0.78 mols Ne = grams/molarmass total mols = nHe + nNe. pHe = XHe*Ptotal pNe = XNe*Ptotal Ptotal = 2.43 atm.