Law Of Synthesis Lab Report

HYPOTHESIS
In this lab, one will expect the mass of the reactants and the mass of the products to remain the same when chemically combined in a closed environment. One can clearly see this is the case since the law states that mass should remain the same, in theory.
OBSERVATIONS
As one can clearly see, the closed Erlenmeyer flask lost no mass. For example, the total mass before mixing was 180.9g and 180.9g after mixing. The law of Conservation of Mass was obeyed in this lab. The results prove the law of Conservation of Mass because one can clearly see that regardless of the errors, we see no between the mass prior to mixing and mass subsequent to mixing. The law of conservation of mass states that the mass of your initial substances (reactants) will be the same as the mass of the substances that you get after the reaction has occurred (products), which is precisely what happened in this experiment.
JUSTIFIED ERRORS

The rubber stopper must have not been closed properly/all the way, or there was a space in it that caused the gaseous material (created from the reaction; CO2) to escape. Thus, this is not a flaw in the law, but rather a flaw in the the doing of the experiment.

Another error that could have occurred. While measuring the Erlenmeyer Flask before mixing it, some of the baking soda might have spilled and reacted to the vinegar, causing some of the mass to evaporate. This causes a difference in the mass prior to mixing, between the closed and opened bag. Yet again, this is rather a flaw in the circumstances and not in the law.