Question
A solution is made by mixing 47.0 mL of ethanol, C2H6O, and 53.0 mL of water. Assuming ideal behavior, what is the vapor pressure of the solution at 20 °C?
Answers
mol fraction EtOH = XEtOH = mols EtOH/total mols.
mol fraction H2O = XH2O = mols H2O/total mols.
mols EtOH = grams/molar mass. You will need to covert mL ethanol to grams by using the density EtOH at 20C.
mols H2O = grams/molar mass. Use density of water at 20C.
pH2O = XH2O * PH2O at 20 C.
pEtOH = XEtOH * PEtOH at 20 C.
Total P = pEtOH + pH2O.
mol fraction H2O = XH2O = mols H2O/total mols.
mols EtOH = grams/molar mass. You will need to covert mL ethanol to grams by using the density EtOH at 20C.
mols H2O = grams/molar mass. Use density of water at 20C.
pH2O = XH2O * PH2O at 20 C.
pEtOH = XEtOH * PEtOH at 20 C.
Total P = pEtOH + pH2O.