Asolution contains 72.0 g of hcl and 468 g of (c6h6). what is the mole fraction of benzene

In order to calculate for the mole fraction of benzene, you will need to convert all mass into moles. This can be done through dividing the mass with the elements’ molar mass. Since the molar mass of HCl is 36, the number of moles of HCl in the solution is 2 moles. Meanwhile Benzene has a molar mass of 78 thus having 6 moles in the solution. Dividing 6 moles with the total number of moles which is 8 moles, you would get 0.75 mole fraction of Benzene. 

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa