Raoults and Henrys Laws Quiz

1
Raoults and Henrys Laws Quiz 42 The total
pressure above a solution of N2 dissolved in
water at 25.0 oC is 514 mm Hg. What is the mole
fraction of the N2 dissolved in the water? The
Henrys law constant for N2 dissolved in water at
25.0 oC is 8.68 x 104 bar. The equilibrium
vapor pressure of water at 25.0 oC is 23.76
mm Hg. PN2 Ptotal - P H2O equil. At
25 C 514 mm Hg - 23.76 mm Hg 490 mm
Hg Since we would expect N2 to only be very
slightly soluble in water, Henrys law will apply
to the N2 XN2 (aq) PN2 / K N2 in water at 25
C (490 mm Hg) (1.00 atm / 760 mm Hg)
(1.01325 bar / atm) -----------------------
--------------------------------------------------
---- (8.68 104 bar) 7.53 10-6