The total mass of the solution be 100 g and the mass of benzene be 30 g.

∴ Mass of carbon tetrachloride = (100 - 30)g

= 70 g

Molar mass of benzene (C₆H₆) = (6 × 12 + 6 × 1) g mol^-1

= 78 g mol^-1

∴ Number of moles of C₆H₆ = \(\frac{30}{78}\)mol

= 0.3846 mol

Molar mass of carbon tetrachloride CCl₄ = 1 x 12 + 4 x 355

= 154 g mol^-1

∴ Number of moles of CCl₄ = \(\frac{70}{154}\)mol

= = 0.4545 mol

Thus, the mole fraction of C₆H₆ is given as

= \(\frac{Number\;of\;moles\;of\;C_6H_6}{Number\;of\;moles\;of\;C_6H_6 + Number\;of\;moles\;of\;CCl_4}\)

= \(\frac{0.3846}{0.3846 + 0.4545}\)

= 0.458