Question

An x molal solution of a compound in benzene has a molefraction =0.2.what is the value of x?

Answer 1

let the total moles be equal to 1 then
the moles of compound are 0.2 and benzene are 0.8
weight of benzene =0.8*78=62.4
molality=moles of solute/mass of solvent
molality=0.2/62.4=0.0032

Answer 2

Let us take total moles will be equal to 1 then and thus it consider the compound that are 0.2 and benzene are 0.8

In addition to this, the weight of benzene is equal to 0.8*78=62.4 and denotes molality is equal to moles of solute/mass of solvent.

Therefore, the molality is measure as 0.2/62.4=0.0032.