Raoults

1
Raoults Henrys Law Quiz Methyl tert-butyl
ether has been used as an oxygenating
gasoline additive, but is also raising concern as
an environmental pollutant. The total pressure
at 25 ?C above an aqueous solution containing
only methyl tert-butyl ether is 70.64 mm Hg. The
equilibrium vapor pressure of water at 25 ?C is
23.76 mm Hg. The Henrys law constant for methyl
tert-butyl ether in water at is 34.29 atm. What
is the mole fraction of methyl tert-butyl ether
in this aqueous solution?
2
In this solution, which well initially assume is
dilute, the solvent, water, should follow
Raoults law, while the solute, methyl tert-butyl
ether (MTBE), should follow Henrys law
Ptotal 70.64 mm Hg PH2O PMTBE
X H2O (aq) P eq, H2O X MTBE (aq) K MTBE in
H2O (aq), 25 C ( 1 - X MTBE (aq) ) 23.76 mm
Hg X MTBE (aq) (34.29 atm ) ( 760.0 mm
Hg ) 23.76 mm Hg 2.604 104 mm Hg X MTBE
(aq) X MTBE (aq) 0.00180