A student weighs an empty flask and stopper and finds the mass to be \(53.256
\mathrm{g}\). She then adds about \(5 \mathrm{mL}\) of an unknown liquid and
heats the flask in a boiling water bath at \(98.8^{\circ} \mathrm{C}\). After
all the liquid is vaporized, she removes the flask from the bath, stoppers it,
and lets it cool. After it is cool, she momentarily removes the stopper, then
replaces it and weighs the flask and condensed vapor, obtaining a mass of
\(53.780 \mathrm{g}\). The volume of the flask is known to be \(231.1
\mathrm{mL}\). The absolute atmospheric pressure in the laboratory that day is
\(728 \mathrm{mm}\) Hg.
a. What was the pressure of the vapor in the flask in atm?
b. What was the temperature of the vapor in \(\mathrm{K}\) ? the volume of the
flask in liters?
c. What was the mass of condensed vapor that was present in the flask?
d. How many moles of condensed vapor were present?
e. What is the mass of one mole of vapor (Eq. 2 )?
