A solution is made using 23.3 percent by mass
CH_(2)Cl_(2)
in
CHCl_(3)
. At
30\deg C
, the vapor pressure of pure
CH_(2)Cl_(2)
is 490 mm Hg , and the vapor pressure of pure
CHCl_(3)
is 260 mm Hg . The normal boiling point of
CHCl_(3)
is 61.7
\deg C
. What is the molality of
CH_(2)Cl_(2)
in the solution?