CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A solid oxide of iron contains only Fe and O. Elemental analysis shows that the compound is 69.94 % Fe by mass.
(a) Assuming a 100.0 g sample, calculate the number of moles of Fe and the number of moles of O present in the sample.
(b) Determine the simplest whole-number ratio of Fe atoms to O atoms and write the empirical formula of the oxide.
(c) Explain why choosing a 100.0 g basis sample is a convenient but not essential step in this calculation.