Question

What is the mass of aluminium in 204 g of the aluminium oxide,Al2O3

Answer 1

Answer:

(204 g)/(101.96 g/mol) = 2.001 mol. 2(2.001) = 4.002 moles of aluminium in the sample. Then there are (4.002 mol)(26.98 g/mol) = 107.97 g of Al. Since the given mass has only 3 significant figures, round this answer to 108 g.