The mass of an atom expressed in atomic mass units * O atomic mass
O atomic mass unit
O atomic number
O mass number
O isotope

The vapour pressure of benzene is 53.3 kpa at 60.6 °c, but it fell to 51.5 kpa when 19.0 g of a non-volatile organic compound was dissolved in 500 g of benzene. calculate the molar mass of the compound.