The empirical formula is the formula given, but only counts one of each.
The question given gives us a composition of 72g Carbon, 12g Hydrogen, & 16g oxygen.
Carbon = C, Hydrogen = H, Oxygen = O
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Remember that the empirical formula only gives one of each, and the three elements inside the question given is Carbon, Hydrogen, and Oxygen. This means that your answer is:
C. CHO: 1 Carbon, 1 Hydrogen, 1 Oxygen.
(C) is your answer
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hope this helps
