Ascorbic acid,C₆H₈0₆,can be represented by the molecular model shown below.If 1.00 mol of ascorbic acid is submitted to combustion analysis,how many moles of CO₂ and how many moles of H₂O would be formed?

Question

Quizplus · Accepted Answer

By examining the molecular model of ascorbic acid, we can see that there are 6 carbon atoms, 8 hydrogen atoms, and 6 oxygen atoms. To find the number of moles of CO₂ produced in combustion analysis, we can first balance the combustion reaction: C6H8O6 + 6O2 -> 6CO2 + 4H2O From the balanced equation, we can see that for every mole of ascorbic acid, 6 moles of CO2 are produced. Therefore, for 1.00 mol of ascorbic acid, we would expect 6.00 mol of CO2 to be formed. To find the number of moles of H₂O produced in combustion analysis, we need to account for the hydrogen atoms in the molecule. For every mole of ascorbic acid, there are 8 moles of hydrogen. In combustion analysis, the hydrogen atoms in the sample react with oxygen to form water: H2 + 1/2O2 -> H2O From the balanced equation, we can see that for every 2 moles of H2, 2 moles of water (H2O) are formed. Therefore, for 8 moles of hydrogen atoms, we would expect 8/2 = 4.00 mol of H2O to be formed. Since each mole of water contains 1 mole of oxygen, we would also expect 4.00 mol of oxygen to be consumed. Therefore, the remaining oxygen (6.00 mol - 4.00 mol = 2.00 mol) would combine with sulfur to form sulfur dioxide (SO2): 2O2 + S -> 2SO2 From the balanced equation, we can see that for every mole of oxygen, 1/2 mole of sulfur are needed. Therefore, for 2.00 mol of oxygen, we would need 2/2 = 1.00 mol of sulfur. Therefore, the products of combustion analysis for 1.00 mol of ascorbic acid would be: - 6.00 mol of CO2 - 4.00 mol of H2O - 1.00 mol of S (to form 2.00 mol of SO2) The question is asking for the number of moles of CO₂ and H₂O, not CO2, H2O, or sulfur dioxide. There is no direct formation of CO₂ or H₂O in the combustion of ascorbic acid, so we need to calculate the formation of these molecules indirectly. To form CO₂, we need carbon and sulfur. From the products of combustion analysis, we have 6.00 mol of CO2 and 1.00 mol of S. We can use the mole ratio from the balanced equation for CO2 to CO₂ (1:1) to find that we would also have 6.00 mol of CO₂. To form H₂O, we need hydrogen, sulfur, and oxygen. From the products of combustion analysis, we have 4.00 mol of H2O and 1.00 mol of S. We can use the mole ratio from the balanced equation for H2O to H₂O (1:1) to find that we would also have 4.00 mol of H₂O. However, we also need to account for the remaining oxygen atoms that did not react with sulfur to form SO2. From the products of combustion analysis, there were a total of 6.00 mol of oxygen atoms, and 4.00 mol were consumed in forming H2O. Therefore, there were 2.00 mol of oxygen atoms remaining. Each mole of H₂O contains 1 mole of sulfur and 2 moles of oxygen, so we would need 2.00 mol of sulfur to react with the remaining 2.00 mol of oxygen. Since we only have 1.00 mol of sulfur, we can only form half the amount of H₂O, which is 2.00 mol. Therefore, the products of combustion analysis for 1.00 mol of ascorbic acid would be: - 6.00 mol of CO2 - 4.00 mol of H2O - 1.00 mol of S (to form 2.00 mol of SO2) - 6.00 mol of CO₂ - 2.00 mol of H₂O The answer is B, 6.00 mol CO₂ and 4.00 mol H₂O.

Ascorbic Acid,C6H806,can Be Represented by the Molecular Model Shown Below

Ascorbic Acid,C₆H₈0₆,can Be Represented by the Molecular Model Shown Below