Conservation of mass is a very real, and very simple concept, it simply is that matter cannot be created or destroyed. in any reaction, physical or chemical, there will always be the same amount of matter on the other side of the reaction or change. we know this because the mass gathered at the beginning of any reaction we observe is the same as the end. Even with gas, we can determine how much was created by simply finding the difference in beginning mass and ending mass. in our experiment, we discovered a line of best fit for the reaction, and determined a predictable relationship between the input (powder) and the output (CO2). This relationship between inputs and outputs will always occur simply because there can be no matter created or destroyed.