The condensed liquid of an unknown has mass of 0.40g. You calculated, when in the vapor phase, that there at 8.7 x 10^-3 mol present in the flask. What is the molecular weight of the unknown molecule?

Answer 1

Molecular weight = grams / moles

0.40 g / 8.7x10-3 mol = 45.97 g/mol = 46 g/mol (2 sig. figs.)