Name
1) A sample of benzene vapor in a flask of constant volume exerts a pressure of 325 mm
Hg at 80°C. The flask is slowly cooled.
a) Assuming no condensation, use the gas laws to calculate the pressure of a vapor at
50°C; at 60°C
b) Compare your answers in (a) to the equilibrium vapor pressures of benzene: 269
mm Hg at 50°C, 389 mm Hg at 60°C.
c) On the basis of your answers to (a) and (b), predict the pressure exerted by the
benzene at 50°C; at 60°C.
2)
Naphthalene, $C_{10}H_8$, is the substance present in some moth balls. Its vapor pressure at
25°C is 0.300 mm Hg.
a) How many milligrams of naphthalene will sublime into an evacuated 1.000-L flask?
b) If 0.700 mg of naphthalene is used, what will the final pressure be? What physical
state(s) of naphthalene is (are) in the flask?
c) If 4.00 mg of naphthalene is used, what will the final pressure be? What physical
state(s) of naphthalene is (are) in the flask?
