An x molal sol. of a compoumd in benzene has mole fraction of solute equal to 0.2 the value of x will be?
Mole fraction of solute = 0.2
Mole fraction of Benzene = 1- 0.2 = 0.8
W.k.t
Mole = Given mass/ molar mass
I.e 0.8 = Given mass / 78
→ Given mass = 78× 0.8 = 62.4
Now
0.2 × 1000 / 62.4 = 3.2