Also, a chemical reaction was observed when mixing sodium carbonate solution with hydrochloric acid. This was indicated by the evolution of gas bubbles in the reaction and the formation of a precipitate. A change in total mass of the starting materials vs. The final products was noted upon weighing the materials before and after the reaction. This is not a contradiction in the law of conservation of matter (mass). This can be explained by the loss of some matter as a gas, which could then not be weighed on a scale.
Some errors in the experiments did occur. In experimenting with the concept of the law of conservation of matter (mass) some mass was lost when transferring liquids some liquid was spilled. No mass was actually destroyed through the chemical reaction. The loss of spilt liquid erroneously seemed to indicate a change in mass between the starting materials and end products. Also, when taking precision measurements of mass down to the one milligram level some human error in measuring was observed.
This could be due to not properly zeroing the scale or allowing the scale to come to a full stop on a number to cause differences in weight of less than 0.05 g between the starting materials and final products.
Both physical and chemical changes were observed in this experiment. These changes were observed and showed the typical signs of each type of change that a physical or chemical reaction has occurred. The overall conclusion of this laboratory experiment was that the law of conservation of matter (mass) held true in all of the chemical experiments. Any deviations from the law of conservation of matter (mass) that were observed could be either explained as an error in weighing or spilling liquid or in the fact that matter that was converted into a gas and could not be weighed using a.