Question

A solution contains 72.0 g of HCl and 468 g of (C6H6). What is the mole fraction of benzene?

0.150
0.331
0.753
0.872

Answer 1

molar mass HCl = 36.5 g/mol      C6H6 = 78 g/mol

number of moles:

1) 72.0 / 39.5 => 1.97 moles
2) 468 / 78 => 6 moles

Total number of mols :

1.97 + 6 => 7.97 moles

mole fraction of benzene :

x₁ = moles benzene / moles total

x₁ = 6 / 7.97

x₁ = 0.753

answer C

hope this helps!