A solution is made by adding 0.100 mole of ethyl ether to 0.500 mole of ethyl alcohol. If the vapor pressures of ethyl ether and ethyl alcohol at 20 oC are 375 torr and 20.0 torr, respectively, the vapor pressure of the solution at 20 oC (assuming ideal behavior) is:

Answer 1

Xether = mols ether/total mols.
Xethanol = mols ethanol/total mols.

pether = Xether*Poether
pethanol = Xethanol*Poethanol.

Totol P = pether + pethanol.