Combustion of a 0.9827-g sample of a compound containing only carbon, hydrogen, and oxygen produced 1.900 g of CO₂ and 1.070 g of H₂O. What is the empirical formula of the compound? A)C₂H₅O B)C₄H₁₀O₂ C)C₄H₁₁O₂ D)C₄H₁₀O E)C₂H₅O₂

Question

Quizplus · Accepted Answer

1. Convert the given masses of the products (COS and H2O) to moles using their respective molar masses:

moles of COS = 1.900 g / 60.07 g/mol = 0.03163 mol
moles of H2O = 1.070 g / 18.015 g/mol = 0.0594 mol

2. Determine the empirical formula using the mole ratios of the elements. Divide each quantity of moles by the smallest number of moles to get the mole ratio:

COS: C = 1, O = 1
H2O: H = 2, O = 1

So the empirical formula is C1H2O1, which can be simplified to CH2O. Therefore, the answer is choice C.