Conservation of mass during a chemical change - Lab Report Example

This is a precipitation reaction and we expect to find a white solid formed as the reaction progresses. The two compounds are products in the Solvay process that is used in the large scale manufacture of sodium carbonate. In our second set up, sodium carbonate is reacted with hydrochloric acid. From our elementary chemistry the products we expect are sodium chloride and carbon IV oxide. Carbon IV oxide will be seen as bubbles emanating from the progressing reaction. Therefore as the carbon IV oxide is lost and this will affect the results as the mass of the products will be less than that of the reactants.

In the first set up 5ml of 1M sodium carbonate was put in a clean test tube and in a different test tube 5ml of 1M calcium chloride was put. The masses of both test tubes with contents were recorded. Then the contents of the two test tubes were mixed. All observations were recorded. After the reaction was completed the contents were weighed again and the mass recorded. In the second set up, 5ml of 1M sodium carbonate was put in a test tube and 5ml of hydrochloric acid put in another. The test tubes were placed in a beaker and the mass of the arrangement taken.

The two were then mixed and all observations recorded as the reaction was progressing. The mass of the set up was taken again after the reaction was over and recorded. The change in mass was 0.137 grams which is negligible. We did not expect the mass to change as using the law of mass conservation as projected by Antoine Lavoisier in 1789, the mass of the reactants should be equal to the mass of the products. There is no compound lost during the reaction and the little change in mass could be due to errors in measurement or the production of heat during the reaction.

The change in mass recorded was 2.597 grams which is significant. Change in mass was expected as there was bubbling taking place as the reaction progressed which