We’re being asked to determine the empirical formula of an unknown compound given the mass percent of C, H, and O.
Recall that the empirical formula is the simplest whole-number ratio formula of a compound.
Step 1: Recall that mass percent is given by:
The problem states that the compound is 74.97% C, 8.39 % H, and 16.64% O. Assuming we have 100 g of the compound, this means we have 74.97 g C, 8.39 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 16.00 g/mol O.
An unknown compound was determined to be 74.97% carbon, 8.39% hydrogen, and 16.64% oxygen. Calculate the empirical formula.