How do I solve this??

Question

Hey sample of aluminum oxide contains 5.33×10²² Atoms . How many aluminum atoms and how many oxygen Atoms are presented? How many grams of aluminum are present in the sample

Answer 1

The formula for aluminum oxide is Al₂O₃

Each molecule of Al₂O₃ contains two Al atoms and 3 O atoms,

So, of the total 5 atoms, 2/5 (40%) are Al and 3/5 (60%) are O atoms

#Al atoms = (0.40)(5.33x10²² atoms) = 2.13x10²² atom of Al

#O atoms = (0.60)(5.33x10²² atoms) = 3.20x10²² atoms of O

To find grams of Al, we first must find moles of Al₂O₃:

5.33x10²² atoms Al₂O₃ x 1 molecule Al₂O₃/5 atoms x 1 mol/6.02x10²³ molecules = 0.642 moles Al₂O₃

Now, find moles of Al and then mass of Al:

0.642 moles Al₂O₃ x 2 mol Al/mol Al₂O₃ x 27.0 g/mol Al = 34.7 g Al