2.2 Calculate the mole fraction of benzene in solution containing by mass in carbon tetrachloride.
For calculating mole fraction, we need moles of both the compounds.
It is given that benzene is in the solution by mass.
So if we consider 100g of solution then 30g is benzene and 70g is CCl4.
Similarly moles of benzene :
So mole fraction of benzene is given :