Absteract: In our second lab our goal was to prove or disprove the law of conservation of mass. We created a chemical reaction which gave off a gas in two trials, one allowed the gas to escape, making the mass seem to disappear. In the other trial we used a bag to capture the escaping air and should have (but didn’t) shown no change in mass. Intro: In this report the lab experiment will be reviewed in hope of recording the results for future reference. The experiment preformed was designed to prove the Law of Conservation of Mass (which states that mass and matter can be neither created nor destroyed. It was believed that the chemical reaction which occurred would show no change in mass after being contained in a bag to prevent loss of gasses. Experimental Methods: -Materials: Baking Soda Vinegar 400mL beaker 100 mL grad. Cylinder Balance Plastic cups, 2 Large plastic bag Twist ties, 2 Weighting papers, 2 -Technique 1. Make a 4 x 3 data table in notebook labeling the first row boxes in this order: Initial mass (g), Final mass (g), and Change in Mass (g). Label the second and third row of the first column as follows: Part 1 and Part 2 2. Set a balance for one sheet of weighing paper then add 4-5g of baking soda, transfer from paper to cup. 3. Fill the 100 mL graduated cylinder to the 100 mL mark (reading from the bottom of the curved surface). Transfer to second cup. 4. Weigh both cups and find total Initial Mass to the nearest hundreth of a gram and record the mass in the table. 5. Remove cups from balance, slowly pour Vinegar into Baking Soda using the wall of the cup to prevent splashing. Gently swirl the cup to ensure solid mix of reactants. Record observations. 6. After end of reaction again weigh both cups to find the final mass of trial one to the nearest hundreth of a gram and record in the data table. 7. Beginning of Trial 2. 8. Set balance for one sheet of weighing paper then add 4-5g of baking soda, transfer from paper to cup. 9. Fill the 100 mL graduated cylinder to the 100 mL mark (again reading from the bottom of curve.) 10. Use 1 twist tie to quarentine the Baking soda in a small section of the bag, then pour in the Vinegar. 11. Weigh the bag and record the mass (to the nearest 0.01g) in the second row of the data table.) 12. Use a twist tie to seal the bag from the top and remove the first twist tie from the lower part of the bag, gently swirl the bag to ensure a well-done mix of reactants. 13. When reactions are over weight the sealed bag and for the final time find the final mass of the mixture to the nearest 0.01 and record in Trial 2 row. Experimental Results: The experiment preformed would be considered a failure if not for the fact that in science there is no such thing as a failure. The bag was not airtight and this resulted in a loss of gasses, throwing off all results. The lab team was left with a +50% margin of error, with the first supposedly less effective trial coming off better than the second trial. This is shown in greater detail later in the report with the Data Chart. Discussion of Results: Though this lab failed to produce evidence that would prove that mass can neither be created nor destroyed, it did however point in the right direction by showing what is the very opposite of it. With an assurance of seal with the bag this lab could be redone and achieve the goal to be found. Conclusion: As the lab began it was intended for proving the Law of Conservation of Mass and though the results could not prove it, success is not far off. The fault of the lab was a leak in a bag critical for sealing the atmosphere long enough to check the mass post-reaction and prove our hypothesis that mass can neither be created nor destroyed correct.