25. A solution is made using 28.3 percent by mass CH₂Cl₂ in CHCl₃. At 30 °C, the vapor pressure of pure CH₂Cl₂ is 490 mm Hg, and the vapor pressure of pure CHCl₃ is 260 mm Hg. The normal boiling point of CHCl₃ is 61.7 °C.
C) what is the mole fraction of CH₂Cl₂ in the solution?