Question

When 3.529 grams of a hydrocarbon, CxHy, were burned, 11.63 grams of CO2 and 3.175 grams of H2O were produced. In a separate experiment, the molar mass of the compound was found to be 40.06 g/mol. Determine the empirical formula and the molecular formula of the hydrocarbon.

a. Empirical formula: CH, Molecular formula: C2H2
b. Empirical formula: CH2, Molecular formula: C4H4
c. Empirical formula: C2H4, Molecular formula: C4H8
d. Empirical formula: C3H6, Molecular formula: C6H12

Answer 1

The empirical formula of the hydrocarbon is CH and the molecular formula is C3H6.

Step-by-step explanation:

To determine the empirical formula and molecular formula of the hydrocarbon, we need to find the molar ratios of carbon and hydrogen in the compound.

First, we calculate the moles of carbon and hydrogen in the CO2 and H2O produced by the combustion of 3.529 grams of the hydrocarbon. Using the molar masses of CO2 and H2O, we find that there are 0.26 moles of carbon and 0.176 moles of hydrogen.

Next, we find the molar ratio of carbon to hydrogen. Dividing the number of moles of carbon by the number of moles of hydrogen, we get a ratio of approximately 1.48:1.

The empirical formula of the hydrocarbon is then CH, and the molecular formula can be determined using the molar mass of the compound. The molar mass is given as 40.06 g/mol, and the molar mass of the empirical formula CH is 13.01 g/mol. Dividing the molar mass of the compound by the molar mass of the empirical formula, we find that the compound's molecular formula is C3H6.