To illustrate the law of conservation of mass that states that matter is neither created nor destroyed during a chemical change Show Background information: This is one of the classic experiments using baking soda and vinegar. The expansion of the balloon with gas provides a tactile experience as the gas is captured rather than being released into the air. The evidence of conservation of mass is supported by the collection of data, by weighing the masses of the reactants before and after the experiment.
Have students practice using talking scales or pan balances, funnels, and measuring of dry and liquid ingredients is helpful before undertaking this experiment. However this experiment also provides opportunities to practice those skills! The total mass of substances that undergo a chemical reaction (reactants) in a chemical reaction must equal the total mass of substances created by the chemical reaction (products). This is called the Law of Conservation of Mass. Early scientists often did not consider that the chemical reactions they were investigating might generate gaseous products. They did not always anticipate that gases in the atmosphere would participate in their experiments. We will be doing an experiment that might have given confusing results for early chemists or alchemists. We will mix baking soda and vinegar in an open beaker. This open system experiment will allow any gases evolved to escape. Hypothesis:When I mix baking soda and vinegar together in an open system, the mass of the reactants (baking soda and vinegar) will equal the mass of the products. Equipment:
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Observations:The reaction proceeded with vigorous bubbling and frothing. Error calculation:((massproducts - massreactants) / massreactants) * 100 = % error ((______ g - _____ g) / ______ g) * 100 = _______ % error Conclusion:I attempted a simple experiment to demonstrate the law of conservation of mass. I hypothesized that following an uncontained baking soda and vinegar reaction (an open system), the mass of the reactants would equal the mass of the products. The data did not support this hypothesis. The mass of the reactants was _____ grams, however the product mass was ______ grams. This was a - ____% error. Aside from the typical errors in measurement that might occur, I believe the error was due to a gaseous product that I did not capture with this experimental setup. During the reaction, I observed a frothy bubbling. This vigorous bubbling decreased during the two or three minutes following the initial reactant mixing. Safely containing all the reaction products should result in the reactant mass equaling the product mass. A sealable plastic bag might be suitable for creating such a closed system if the volume of the gases was small. How does the conservation of mass relate to baking soda and vinegar?A chemical reaction takes place when vinegar and baking soda are mixed. One of the new substances formed is carbon dioxide gas. If the carbon dioxide gas is contained, the mass of the substances will stay the same according to the Law of Conservation of Mass. If the gas is allowed to escape, the mass will be less.
What is the science behind the vinegar and baking soda experiment?Sodium bicarbonate and acetic acid reacts to carbon dioxide, water and sodium acetate. The solid baking soda was placed in liquid vinegar producing carbon dioxide gas, which is evident because of the formation of bubbles in the foaming mixture.
What happens when you put baking soda and vinegar together?Mixing baking soda (sodium bicarbonate) and vinegar (acetic acid) causes a chemical reaction that produces a salt (sodium acetate) and water, as well as carbon dioxide gas.
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