Problem: An unknown compound was determined to be 74.97% carbon, 8.39% hydrogen, and 16.64% oxygen. Calculate the empirical formula

FREE Expert Solution

Recall that the empirical formula is the simplest whole-number ratio formula of a compound


Recall that mass percent is given by:


% mass=mass of Xtotal mass×100


Assuming we have 100 g of the compound, this means we have 74.97 g C, 8.39 g H, and 16.64 g O.



Now, we need to get the moles of each element in the compound. 

The atomic masses are 12.01 g/mol C, 1.01 g/mol H, and 16 g/mol O.


74.97 g C×1 mol C12.01 g C = 6.24 mol C


8.39 g H×1 mol H1.01 g H = 8.31 mol H


16.64 g O×1 mol O16.00 g O = 1.04 mol O



Now, we need to divide the number of moles of each by the smallest value, 1.04 mol, to get the smallest ratio of C, H, and O.

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Problem Details

An unknown compound was determined to be 74.97% carbon, 8.39% hydrogen, and 16.64% oxygen. Calculate the empirical formula

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