Neil Ms.Parkhurst Chemistry 10/3/2012 Law of Conservation of Mass Inquiry Lab Background In the 19th century, Antoine Lavoisier discovered the Law of Conservation of Mass, the Law of Conservation of Mass states that mass is neither created nor destroyed during ordinary chemical reactions or physical changes.A Closed System can not exchange any of heat, work, or matter with the surrounding.
An Open System can exchange all of heat, work, or matter. It allows interactions between its internal elements and the environment. Purpose
The purpose of this lab was to designed and complete a laboratory experiment that proves the law of conservation of mass. Procedure First of all, a flask was taking out and filled in with 15ml of water. The mass of the flask & water was determined and recorded. Then, an Alka Seltzer tablet was filled in the water. After a while, placed the flask & water & Alka Seltzer tablet on to the balance pan, the mass of the whole system was determined. This procedure was for the open system. For the close system, a flask was taking out and filled in with 15ml of water.
The mass of the flask & water was determined and recorded. Then, an Alka Seltzer tablet was placed in a balloon, and put the balloon on the top of the flask, the Alka Seltzer tablet fell into the water. After the reaction was done, measured the mass of it, recorded it into the data table. IV. Data Table Data of Law of Conservation of Mass | |Mass | |Open system before |126. 3g | |Open system after |126. 09g | |Closed system before |143. 65g | |Closed system after |145. 21g | Conclusion and Analysis The mass of the open system before was 126. 53g, and the mass of open system after was 126. 09g. The mass of closed system before was 143. 65g, after was 145. 21g.
Both set of data were close enough to justify the law of conservation of mass which is the mass were about the same before and after a reaction. According to the reaction, which was H2O + NaHCO3 = CO2 + H2O + NaOH, showed that there were some gas which was CO2 were produced. According to the law of open and closed system, the CO2 were escaped from the open system, on the other hand, it were keep in the closed system. Because of that, the open system was missing some of the mass of gas, it made the first procedure differ from the second procedure.