A chemist is tasked with determining the molar mass of a volatile organic compound
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A chemist is tasked with determining the molar mass of a volatile organic compound. A 0.842 g sample of the substance is vaporized in a 250.0 mL flask immersed in a boiling-water bath maintained at 95.0 °C. When the substance has completely vaporized, the pressure inside the flask is measured to be 735 mmHg. Assume the vapor behaves ideally and completely occupies the flask.
(a) Convert the measured pressure and temperature to units appropriate for an ideal-gas calculation, showing your work.
(b) Calculate the number of moles of vapor present in the flask.
(c) Determine the molar mass of the compound from the data provided.
(d) The empirical formula of the compound is known to be C3H4O. Propose a plausible molecular formula that is consistent with your molar-mass determination, and briefly justify your selection.