Answer: B. Find the percentage of each element first.
%H = 13.33%. Oxygen is twice the mass of hydrogen, so %O = \(2 \times 13.33\% = 26.67\%\). The remainder is carbon: %C = \(100 - 13.33 - 26.67 = 60\%\).
Convert to moles per 100 g sample: C = 60/12 = 5.00; H = 13.33/1 = 13.33; O = 26.67/16 = 1.667.
Divide by the smallest (1.667): C : H : O = 3 : 8 : 1.
Empirical formula = \(\text{C}_3\text{H}_8\text{O}\) (propan-1-ol or propan-2-ol).
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