A student weighed an empty flask and stopper and found the mass to be \(53.256
\mathrm{g}\). She then added about five milliliters of an unknown liquid and
heated the flask (in a boiling-water bath) to \(98.8^{\circ} \mathrm{C}\). After
all the liquid had vaporized, she removed the flask from the bath, stoppered
it, and let it cool. Once it had cooled, she momentarily removed the stopper,
then replaced it and weighed the flask and condensed vapor, obtaining a mass
of \(53.870 \mathrm{g}\). The volume of the flask was known to be \(271.1
\mathrm{mL}\). The absolute atmospheric pressure in the laboratory on that day
was \(728 \mathrm{mm}\) Hg.
a. What was the pressure of the vapor in the flask in atm?
\(P=\)___________atm
b. What was the temperature of the vapor in \(\mathrm{K}\) ? What was the volume
of the flask in liters?
\(T=\)___________ \(\mathbf{K}\) \(\quad\) \(V=\)___________\(\mathbf{L}\)
c. What was the mass of condensed vapor that was present in the flask?
\(m=\)__________grams
d. How many moles of condensed vapor were present?
\(n=\)__________moles
e. What is the mass of one mole of vapor (Eq. 2)?
\(M M=\)__________\(g /\) mole
