Determine the empirical formula (1 Viewer)

[nsbrando]

Determine the empirical formula of magnesium oxide???

Mass of dry crucible + Lid = 32.14g
Mass of dry crucible + Lid + Magnesium = 32.63g
Mass of dry crucible + Lid + Magnesium oxide = 32.95g

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[Living Moment]

What course are you doing buddy? you mostly ask Q. that aren’t syllabus =/

 

[jackerino]

Mass of magnesium is 32.63-32.14=0.49g, mass of oxygen=32.95-32.63=0.32g.

So how many moles do you have? Divide mass by the atomic weight of magnesium (24.3), and you get 0.0201.
Divide g of oxygen by atomic weight (16.0), and you get a mole number of 0.0200.

Divide by the small quantity to get an integer ratio for at least one element, and you get a ratio of Magnesium to oxygen as 1.005:1

Therefore seeing as the difference is so small, you round off the 0.05 to make it a 1:1 ratio, hence MgO