Molecular m of volatile liquid?

A sammple of unknown liquid is vaporized in a flask having a volume of 152.2mL and open to the atmosphere through a pin hole. On a day when the atmospheric pressure is 756.2 torr, the sample is vaporized in an oil bath at 225.2 C. the m of the vapor is found to be 1.0050g. Determine the gram moecular m of the unknown liquid.