A solution is made by mixing 37.0 mL of ethanol, C2H6O, and 63.0 mL of water.?

Assuming ideal behavior, what is the vapor pressure of the solution at 20 °C?

ethanol: 0.789 g/mL 43.9 torr
water : 0.998 g/mL 17.5 torr

3 answers

Use density to convert volume ethanol and volume H2O to grams.
mols ethanol = grams/molar mass
mols H2O = grams/molar mass

Xethanol = nethanol/total mols.
XH2O = nH2O/total mols.

pethanol = Xethanol*Po ethanol
pH2O = XH2O*Po H2O.

Total P solution = pH2O + pethanol.

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