what are the mole fraction of benzene?

Question

what are the mole fraction of benzene (C6H6), and toluene (C7H8),in a solution prepared by adding 500 g of benzene to 500g of toluene?
plz someone explain it!!!!

Answer 1

In terms of moles, 500 g of benzene is more than 500 g of toluene. Benzene has a mol wt of 78, so 500 g is 500/78 moles. Toluene (C6H5-CH3) has a mol wt of 92, so 500 g is 500/92 moles. The mole fraction of benzene is (500/78) divided by the SUM of the two component moles
(500/78)+(500/92) and that of toluene 1-mole fraction benzene.

Answer 2

C6H6 Mol.mass = (12 x 6) + (1 x 6 ) = 78 g/mole.
C7H8 Mol.mass = (12 x 7) + (1 x 8) = 92 g/mole.
C6H6 = Mass/Mol.mass = 500/78 = 6.41 moles
C7H8 = Mass/Mol.mass = 500/92 = 5.44 moles.
Total No. of moles = 11.85.
Mol.fraction C6H6 = 6.41 ÷ 11.85 = 0.5409 (54.09%)
Mol.fraction C7H8 = 5.44 ÷ 11.85 = 0.4591 (45.91%)