1. Measure the mass of a beaker, 10mL vinegar, and 10g baking soda.
2. Mix the compounds in the beaker and wait for the reaction to finish.
3. Record the mass of the beaker and its contents.
4. Determine the remaining mass of the chemicals in the beaker.
5. Measure the mass of a new beaker, a plastic weight boat, 10mL vinegar, and 10g baking soda.
6. Mix the compounds in the beaker, and immediately place the plastic boat over the beaker so that it acts as a lid, and wait for the reaction to finish.
7. Record the mass of the beaker, its contents, and the plastic boat.
8. Determine the remaining mass of the chemicals in the beaker.
9. Cut a sheet of plastic wrap large enough to cover the top of the beaker, with extra room so that it can be rubber banded to the sides of the beaker.
10. Measure the mass of a beaker, a rubber band, the sheet of plastic wrap, 10mL vinegar, and 10g baking soda.
11. Mix the compounds in the beaker, and immediately place the plastic wrap over the beaker and rubber band it to the sides so that it traps all of the contents of the beaker inside, and wait for the reaction to finish.
The Essay on Mass Determination
Objective: The purpose of this experiment is to see the difference of precision of different balances. When doing experiments we determine the mass my measuring the sample with a balance. There are many kinds of balances that measure to different precisions. This experiment shows the different results that two balances can give. Summary of Procedures Determine the mass with the triple beam scale ...
12. Record the mass of the beaker, its contents, the sheet of plastic wrap, and the rubber band.
13. Determine the remaining mass of the chemicals in the beaker. 14. Repeat steps 10-13 to obtain a second set of data, to amount to 4 reactions completed.
*During Reaction #2 the reaction rose too quickly and some of the contents were lost.
The beakers weighed differently from each other, because we did not use the same beaker for all tests. The masses of the baking soda, and of the vinegar are also different, because we lack the tools to be completely accurate, although we tried to get as close as possible. During Reaction #2 there was a problem. As the reaction was in progress we tried to place the plastic weight boat over the beaker, but because the reaction was so “explosive” the contents of the beaker leaked over the top, overall making the “mass” of the chemicals inaccurate. Another problem for my group was that we ran out of time, and weren’t able to obtain a second set of data for the 3rd reaction, because the time limit expired before we completely finished the reaction.
Conclusion:
In this lab experiment, ultimately the goal is to determine if mass is conserved in a chemical reaction. This means that you will have the same mass starting as you have when you finish the reaction. Overall our data showed us that we did have almost the same amount of chemicals starting, as we did after we finished. This could be because our measurements were not 100% accurate, or because mass actually was conserved. If we had completely accurate scientific equipment when we tested this experiment it could possibly show that there was .01g less chemicals after reaction, but from the measurements we gathered using our equipment, it can safely be assumed that mass is conserved during a reaction.
