How do I find the percentage composition of Nitrogen in N_2O5?

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How do I find the percentage composition of Nitrogen in #N_2O_5# ?

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Answer 1 · 2016-03-08T22:57:54

You need to take the ratio of the mass of nitrogen to the mass of the entire molecule.

This is actually fairly straight-forward.

You know that #N_2O_5# has two nitrogen atoms and five oxygen atoms.

You also know how much a mole of #N_2O_5# masses (2 x 14.007 + 5 x 15.9994), or 108.011 grams per mole.

So the question really is, what % of the mass of a mole of #N_2O_5# is nitrogen?

That would be the total mass of nitrogen, 2 x 14.007 divided by 108.011, and multiplied by 100%.

If you've done everything correctly, you should get: 25.936247234%.

Adjusting to 5 significant figures: 25.936%