CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A white solid contains only aluminum and oxygen. A 2.50 g sample of the solid is found to contain 1.33 g of aluminum by mass.
(1) Calculate the mass of oxygen present in the sample.
(2) Determine the mass percent of each element in the compound.
(3) Using the data, calculate the empirical formula of the compound. Clearly show all mole calculations and simplifications to whole-number ratios.
(4) The molar mass of the compound is experimentally determined to be 1.02 × 10² g mol⁻¹. Determine the molecular formula of the compound and justify your result.