Data Sheet Name_____________________________ 1. Determine the molar mass of sodium bicarbonate (from periodic table). molar mass of Na _______________ x 1 mol Na = _______________ molar mass of H _______________ x 1 mol H = _______________ molar mass of C _______________ x 1 mol C = _______________ molar mass of O _______________ x 3 mol O = _______________ Sum for total molar mass _______________ 2. Determine the number of moles of sodium bicarbonate in your sample of baking soda: Run I grams of sodium bicarbonate (from experiment): molar mass of sodium bicarbonate (from #1 above) number of moles of sodium bicarbonate _______________ _______________ _________________ Run II grams of sodium bicarbonate (from experiment): molar mass of sodium bicarbonate (from #1 above) number of moles of sodium bicarbonate _______________ _______________ _________________ Run III (which was optional) grams of sodium bicarbonate (from experiment): molar mass of sodium bicarbonate (from #1 above) number of moles of sodium bicarbonate AACE _______________ _______________ _________________ Copyright © 2000 by Doris Kimbrough, all rights reserved Page 1 of 4 3. Determine the mass of acetic used in the experiment. If your vinegar is 4 %, this means that every 100 g of vinegar contains 4 g of acetic acid. (If it is 5 %, then 100 g contains 5 g of acetic acid). Run I: 4 grams acetic acid ? grams acetic acid 100 grams of vinegar ______ grams of vinegar This is the mass of vinegar you measured in the 1st experiment. Run II: 4 grams acetic acid ? grams acetic acid 100 grams of vinegar ________ grams of vinegar This is the mass of vinegar you measured in the 2nd experiment. Run III: 4 grams acetic acid ? grams acetic acid 100 grams of vinegar _______ grams of vinegar 4. Determine the molar mass of acetic acid, C3H4O2. molar mass of C _______________ x 3 mol C = _______________ molar mass of H _______________ x 4 mol H = _______________ molar mass of O _______________ x 2 mol O = _______________ Sum for total molar mass _______________ 5. Determine the number of moles of acetic acid in each sample of vinegar. Run I grams of acetic acid (from #3 above): _______________ molar mass of acetic acid (from #4 above) _______________ number of moles of acetic acid _________________ AACE Copyright © 2000 by Doris Kimbrough, all rights reserved Page 2 of 4 Run II grams of acetic acid (from #3 above): _______________ molar mass of acetic acid (from #4 above) _______________ number of moles of acetic acid _________________ Run III (which was optional) grams of acetic acid (from #3 above): _______________ molar mass of acetic acid (from #4 above) _______________ number of moles of acetic acid _________________ 6. Determine the total mass gain or loss for the reaction by comparing your initial mass (combined mass of baking soda and vinegar) to your final mass. Run I: Initial total mass Run II: __________ Run III: Initial total mass __________ Initial total mass Final total mass __________ Final total mass Difference Difference __________ Final total mass __________ __________ Difference __________ __________ __________ 7. Calculate the molar mass of carbon dioxide. molar mass of C _______________ x 1 mol C = _______________ molar mass of O _______________ x 2 mol O = _______________ Sum for total molar mass _______________ 8. Determine the number of grams of carbon dioxide that the reaction should theoretically produce, remembering that one mole of acetic acid or sodium bicarbonate should produce one mole of carbon dioxide Run I: moles of carbon dioxide* __________ molar mass of carbon dioxide (from #7) X__________ grams of carbon dioxide (the product) ___________ Run II: moles of carbon dioxide* __________ molar mass of carbon dioxide (from #7) X__________ grams of carbon dioxide (the product) ___________ Run III: moles of carbon dioxide* __________ molar mass of carbon dioxide (from #7) X__________ grams of carbon dioxide (the product) ___________ *moles of carbon dioxide = moles of acetic acid (from #5 above) AACE Copyright © 2000 by Doris Kimbrough, all rights reserved Page 3 of 4 Questions (attach answers) 1. Figure out why the mass increased or decreased. Correlate this increase or decrease to the products yielded by the reaction. Does the stoichiometry of the reaction (coupled with the results of the calculations above) account for all of the mass difference? Discuss possible reasons for any discrepancies. 2. In this particular example the change in mass through the course of the reaction provides evidence that a reaction is taking place. Is it necessary to have a change in mass in order to have a reaction? Can you provide an example of a reaction where no mass change would be observed? 3. (Extra credit) Explain how this particular reaction might be supportive of the phlogiston theory that was popular among scie AACE Copyright © 2000 by Doris Kimbrough, all rights reserved Page 4 of 4