A solution is made by mixing 48.0 ml of ethanol, c2h6o, and 52.0 ml of water. assuming ideal behavior, what is the vapor pressure of the solution at 20 °c?

The mass of ethanol = 0.789 g/ml (48) = 37.872 g

Number of moles of ethanol = 37.872 g / 46g/mol = 0.8233 moles

Mass of water = 52 x 1g/ml = 52 g

Number of moles of water = 52 / 18 g/mol = 2.889 moles of water

We can calculate the mole fraction;

Mole fraction of ethanol = 0.8233/3.712 = 0.2218

Mole fraction of water = 2.889/3.712 = 0.7782

But P° (1) Vapor pressure of pure water = 17.5 torr

while P° (2) vapor pressure of pure ethanol = 43.9 torr

P (1) = 0.7782 * 17.5 = 13.6185

P (2) = 0.2218 * 43.9 = 9.7370

Therefore, the P (s) = 23.3555