What is the vapor pressure (in mm Hg) of a solution of 12.5 g of glucose ( C6H12O6) in 75.0 g of methanol (CH3OH) at 27 degrees celcius? The vapor pressure of pure methanol at 27 degrees celcius is 140 mm Hg.

Answer 1

moles glucose = grams/molar mass.
moles methanol = grams/molar mass.
X_methanol = moles CH3OH/total moles.

Psoln = Xmethanol*P^o_methanol.

Answer 2

134.728 mm Hg