An oxide of phosphorus contains 56.4% phosphorus and 43.6% oxygen. it's relative molecular mass is 220. find both the empirical and the molecular formula of the oxide'

Moles of P = 56,4g/30,974g/mole = 1,82 moles P
moles of O = 43,6/15,999 = 2,73 moles of O

converting to the simplest ratio:
For P : 1,82/1,82 = 1
For O : 2,73/1,82 = 1,5

1 P and 2 oxygens.
PO2 -> the empirical formula

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