Calculating the RMM of compounds

The relative molecular mass of a compound, often called its RMM, is the sum of the mass of all the atoms in the compound.

So the RMM of Fe₃(PO₄)₂ is the sum of the mass of three Fe atoms plus two P atoms plus eight O atoms. It's just arithmatic, really.

The questions are selected at random from a group of 30, so occassionally you get asked the same question twice. You can attempt as many questions as you like, it's for your benefit.

The relative atomic masses you will need are give on the question page.

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