Solution :-
formula to calculate the vapor pressure of the solution is as
follows
Vapor pressure of solution = mole fraction of solvent * vapor
pressure of pure solvent
lets first calculate the mole fraction of the ethanol
mole fraction of ethanol = moles of ethanol / total moles
                                Â
= 15.30 mol / (15.30 mol + 2.13 mol )
                               Â
= 0.8778
now lets calculate the vapor pressure of the solution
Vapor pressure of solution = mole fraction of solvent * vapor
pressure of pure solvent
                                     Â
= 0.8778 * 760 torr
                                     Â
= 667 torr
Therefore vapor pressure of the solution = 667
torr