Three gases (8.00 g of methane, CH4, 18.0 g of ethane, C2H6, and an unknown amount of propane, C3H8) were added to the same 10.0-L container. At 23.0 ∘C, the total pressure in the container is 4.50atm . Calculate the partial pressure of each gas in the container.

Question

Three gases (8.00 g of methane, CH4, 18.0 g of ethane, C2H6, and an unknown amount of propane, C3H8) were added to the same 10.0-L container. At 23.0 ∘C, the total pressure in the container is 4.50atm . Calculate the partial pressure of each gas in the container.
Express the pressure values numerically in atmospheres, separated by commas. Enter the partial pressure of methane first, then ethane, then propane.

DrBob222 · Answer

Use PV = nRT and solve for n = total mols

mols CH4 = grams/molar mass = ?
mols C2H6 = grams/molar mass = ?
mols unknown gas = total mols - mols CH4-mols C2H6.

mol fraction = XCH4 = mols CH4/total mols.
XC2H6 = mols C2H6/total mols
Xunknown = mols unkn/total mols

pCH4 = XCH4*Ptotal
pC2h6 = XC2H6*Ptotal
punk = Xunk*Ptotal