A 4.235 g sample of a hydrocarbon was burned in oxygen to give 3.810 g of H2O and 13.96 g of CO2. What is the empirical formula of the compound?

To find the empirical formula of the compound, we need to determine the moles of each element in the compound.

1. First, we need to find the moles of hydrogen and carbon in the compound. We can do this by using the molar masses of water (H2O) and carbon dioxide (CO2), and the given masses of these compounds.

   The molar mass of H2O is approximately 18.015 g/mol, and the molar mass of CO2 is approximately 44.01 g/mol.

   The moles of hydrogen can be calculated as follows: Moles of H = mass of H2O / molar mass of H2O = 3.810 g / 18.015 g/mol = 0.211 moles

   However, since each molecule of water contains 2 atoms of hydrogen, the moles of hydrogen in the hydrocarbon is 2 * 0.211 = 0.422 moles.

   The moles of carbon can be calculated as follows: Moles of C = mass of CO2 / molar mass of CO2 = 13.96 g / 44.01 g/mol = 0.317 moles

2. Now, we need to find the ratio of the moles of hydrogen to the moles of carbon. This can be done by dividing the moles of hydrogen by the moles of carbon.

   Ratio of H to C = moles of H / moles of C = 0.422 / 0.317 = 1.33

3. Since the empirical formula represents the simplest whole number ratio of the elements in the compound, we need to round the ratio to the nearest whole number. In this case, the ratio of H to C is approximately 1:1.

Therefore, the empirical formula of the compound is CH.