The vapour pressures of chloroform CHCl 3 , dichloromethane CH 2 Cl 2 at 298 K are 200 mmHg and 415 mmHg , respectively. An ideal solution is prepared by mixing 59 . 75 g of CHCl 3 and 21 . 25 g of CH 2 Cl 2 , the mole fractions of chloroform and dichloromethane in vapour phase, respectively are

Step-by-step solution

The expression for moles of CHCl 3 is given as, n = m CHCl 3 M CHCl 3 = 59 . 75   g 119 . 5   g · mol - 1 = 0 . 5   mol The expression for moles of CH 2 Cl 2 is given as, n = m CH 2 Cl 2 M CH 2 Cl 2 = 21 . 25   g 85   g · mol - 1 = 0 . 25   mol The mole fraction of CH 2 Cl 2 , is given as: χ CH 2 Cl 2 = n CH 2 Cl 2 n CH 2 Cl 2 + n CHCl 3 = 0 . 25 0 . 25 + 0 . 5 = 1 3 The mole fraction of CHCl 3 in vapour phase is given as: y CHCl 3 = p CHCl 3 p 1 0 + p 2 0 - p 1 ° x