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Multiple Choice
Upon combustion, a 0.8009 g sample of a compound containing only carbon, hydrogen, and oxygen produces 1.6004 g CO2 and 0.6551 g H2O. What is the empirical formula of the compound?
A
C3H6O2
B
C2H4O
C
CH2O
D
C2H4O2
Verified step by step guidance
1
Determine the moles of carbon in the compound by using the mass of CO2 produced. Use the molar mass of CO2 (44.01 g/mol) to find the moles of CO2, and then use the ratio of carbon in CO2 to find the moles of carbon. The formula is: \( \text{moles of C} = \frac{\text{mass of CO2}}{44.01} \times 1 \).
Determine the moles of hydrogen in the compound by using the mass of H2O produced. Use the molar mass of H2O (18.02 g/mol) to find the moles of H2O, and then use the ratio of hydrogen in H2O to find the moles of hydrogen. The formula is: \( \text{moles of H} = \frac{\text{mass of H2O}}{18.02} \times 2 \).
Calculate the mass of carbon and hydrogen in the compound using their respective moles and atomic masses (C: 12.01 g/mol, H: 1.008 g/mol). Subtract the sum of these masses from the total mass of the compound to find the mass of oxygen. The formula is: \( \text{mass of O} = \text{total mass} - (\text{mass of C} + \text{mass of H}) \).
Determine the moles of oxygen in the compound using the mass of oxygen calculated in the previous step and the atomic mass of oxygen (16.00 g/mol). The formula is: \( \text{moles of O} = \frac{\text{mass of O}}{16.00} \).
Find the simplest whole number ratio of moles of carbon, hydrogen, and oxygen to determine the empirical formula. Divide each of the moles by the smallest number of moles calculated in the previous steps to get the ratio. Adjust the ratio to the nearest whole numbers to find the empirical formula.