How do I find the formula of the compound given the ratio of its constituents by weight? [closed]








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Problem : An organic compound containing carbon, nitrogen and oxygen will have a weight ratio $9:1:3$. The molecular weight of the compound is $108$. What is the formula of the compound?


I thought of calculating the empirical formula, but percentages are given for that, and not weight. 




It's an algebra problem.


108 = 9x + 1x + 3x


Solve for x.


Weight of carbon per molecule = 9x
Weight of nitrogen per molecule = 1x
Weight of oxygen per molecule = 3x


Then convert from weights to numbers (I assume you know how to do that :) ).


Note that the result is rather nonsensical, as it gives you fractional atoms.


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