Chemical Change Lab Report

The purpose of this lab was to determine if a change in mass occurs during a chemical reaction in a closed system. To conduct this experiment, the mass of the test tube, rubber cover, and other materials must be measured. To prevent the test tube from rolling off of the balance, a plastic cup was used to hold it in place, but the group had to remember to zero out the cup on the balance so the cup’s mass will not affect the masses of the objects the group was trying to measure. During this investigation, it was determined that there is a 0% change in mass after a chemical change in a closed system, because the mass of the copper and sulfur before heating did not change after being heated. Although the substances had changed in appearance and could no longer be considered …show more content…
When comparing with class data, the majority of the class got the result of having no change in mass during a chemical reaction. Most of the few groups got different results were acceptable once the sensitivity of the balance was considered, such as a change in mass of 0.01. In the class data there were only a few outliers, and the overall trend of the class data was that there was no change in mass, or a 0% change in mass. This suggests that there is no change in mass during a chemical reaction, which supports the Law of Conservation of Mass, which states that mass cannot be created or destroyed, on transformed. Clearly, the mass of the substances were transformed into a new substance, but the substance that was created by heating copper and sulfur had the same mass as before undergoing a chemical change. A possible error that may have been encountered is that the group forgot to zero out the cup while measuring the masses of the materials, therefore including the cup’s mass in the group’s measurements and causing an apparent increase in