Answer:
The vapor pressure = 345.8 torr
Explanation:
Step 1: Data given
Number of molesof a non-volatile solute = 0.500 moles
mass of hexane = 275 grams
Molar mass of hexane = 86.18 g/mol
Temperature =49.6 °C
P°(hexane) = 400.0 torr at 49.6°C.
Step 2: Calculate moles solvent
moles of solvent = 275 grams / 86.18 g/mol = 3.19 mol
Mol fraction of the solvent = 3.19 moles / (0.500 + 3.19) = 0.8645
Step 3: Calculate the vapor pressure
P = P° * Xsolvent
⇒ with Xsolvent = mol fraction of the solvent = 0.8645
⇒ with P° hexane =400.0 torr
P = 400.0 * 0.8645 = 345.8 torr
The vapor pressure = 345.8 torr
