Combustion analysis of an unknown hydrocarbon produced the following results: C 59.96%, H 13.42%, and O 26.62%. Determine the empirical formula. A) C₃H₈O B) C₈H₈O₂ C) C₅H₈O₄ D) C₆H₁₆O₄ E) C₉H₁₆O₂

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Quizplus · Accepted Answer

The empirical formula is determined by converting the percentage composition to moles: C: 59.96 g / 12.01 g/mol = 4.99 mol, H: 13.42 g / 1.008 g/mol = 13.31 mol, O: 26.62 g / 16.00 g/mol = 1.66 mol. Dividing by the smallest number of moles (1.66), we get C: 3, H: 8, O: 1, which corresponds to C₃H₈O.

Combustion Analysis of an Unknown Hydrocarbon Produced the Following Results