the major commercial aluminium ore is bauxite,AlO3.H2O(s).What is its molar mass?The analysis of a representive sample of bauxite shows it contains 70% by mass of Al2O3..What is the maximum mass of aluminium metal that could be obtained from 200kg of bauxite by the HAll electrolytic process?

Answer 1

look up the atomic masses in your periodic table. Add up the appropriate multiples to get the molecular molar mass.

The rest is just algebra, if you know the yield of the Hall process.