Answer:
.133
Step-by-step explanation:
Dissolution of solute lowers the vapor pressure of solvent .
Relative lowering by non -volatile solute is equal to mole fraction of solute dissolved .
Vapor pressure of pure water is 2.33 k Pa
Lowering of vapor pressure = 2.33 - 2.02 = .31 k Pa .
relative lowering = .31 / 2.33 = .133
relative lowering will be equal to mole fraction of non volatile solute like NaCl
so mole fraction of NaCl dissolved = .133