Investigation for the Conservation of Mass Research Question: How does the increasing volume (0.5mL for each trial) of acetic acid (Vinegar) combined with 1g of sodium bicarbonate (Baking Soda) affect the volume of carbon dioxide produced after the chemical reaction, while using a graduated cylinder as a measuring tool? Background Information:This experiment is to prove the law of conservation of mass by using the two main compounds, baking soda, and vinegar. These materials are used because they are easy to handle, safe, cost-efficient and give an almost instant chemical reaction (quick results). Atoms can be neither created nor destroyed during a chemical reaction and the number of atoms of each element must remain the same prior and after the chemical reaction. Thus, if the number of atoms for each element must be the same, then the mass can never change in a chemical reaction, meaning that the mass of all reactants and products are equal (Sterner).
Hypothesis: If the volume of acetic acid increases, then the volume of carbon dioxide will increase as well. This is because the Law of Conservation of mass indicates that mass cannot be created nor destroyed (Lumen). Meaning that the total mass of all reactants is equivalent to the mass of all products even after a chemical reaction.Independent Variable: Unit:Range of IV: Amount of Acetic Acid CH3COOH(aq) mL0.5 mL, 1 mL, 1.5 mL, 2 mL, 2.5 mLIt will be measured by using the weigh boat and an electronic scale. Dependent Variable:Unit:How it is being measured: CO2(g)The volume of carbon dioxide produced by the Chemical Reaction.
mLIt will be measured by looking at the amount of water (mL) lost in the graduated cylinder after combining baking soda and vinegar. Control Variable: Rationale: Same amount of water in the graduated cylinder. It should be filled airtight without any bubbles to ensure that the graduated cylinder is fully filled. (100ml of water)The same amount of Sodium Bicarbonate As the dependent variable is the mass of the sodium bicarbonate, it should be measured with the weigh boat and electronic scale to make sure that 1g is precisely being combined with the acetic acid. 1g should be used for every trial for each level. Same Room Temperature Room temperature should remain at a constant 22 degrees to ensure that the process of the reaction is not altered.
(Sped up or slowed down) The concentration of vinegar There are many types of vinegar, all which have has different concentrations of acidity and PH Levels. So if more than one type of vinegar is used, the results will be drastically different. The vinegar used in this experiment is Heinz Vinegar which is has a PH level of 2.4. The same type of Sodium Bicarbonate When Sodium Bicarbonate is left out for too long or expired, the level of reactivity can be affected. The expired baking soda will not react immediately or at all when acetic acid is combined with it. Which is why it is important to use the same batch and brand of baking soda for the experiment. Same measuring tools should be used for each level and trialThe same beaker, flask, graduated cylinder, tube, clamp, retort stand and electronic scale should be used for every trial for each level.
Materials: Sodium bicarbonate 22.5 grams (0.5, 1, 1.
5, 2, 2.5 grams x 3 trials for each level)Vinegar 15g (1ml x 15 trials) Water (1x) Beehive shelf (1x) 10 mL graduated cylinder (1x) 100mL graduated cylinder (1x) 50 mL Glass Beaker (1x) Rubber Tube (1x) Plastic Container (1x) Retort Stand (1x) Clamp(1x) Spatula (1x) Side arm erlenmeyer flask (1x) Rubber Stopper (5x) Weigh Boat (1x) Electronic scale Method: Setup Procedure: Firstly, prepare all of the materials as stated above. Fill the plastic container to the top with waterPlace the beehive shelf in the plastic container, making sure it is almost fully submerged. Place the 100mL graduated cylinder into the water, the mouth facing downwards over the beehive shelf. Making sure there are no gas bubbles in the cylinder. Using the clamp, attach the Erlenmeyer flask to the retort stand. Connect the plastic tube from the Erlenmeyer flask under the beehive shelf, through the hole, and into the graduated cylinder.
(make sure no water escapes while doing this)Data Collection Procedure: Using the spatula, scoop exactly 1g of sodium bicarbonate powder onto a weigh boat. Press “Tear” on the electronic scale every time before weighing. Put the weigh boat on the electronic scale for accuracy and scoop out any excess or to add more.
Transfer the sodium bicarbonate powder into a small piece of aluminum foil that has an opening in the foil. With a graduated cylinder, measure 0.5 mL of acetic acid and add it to the Erlenmeyer flask. Add both compounds to the Erlenmeyer flask. Quickly use a rubber stopper to seal the Erlenmeyer flask and to prevent the gas from the chemical reaction to leak out.
Immediately connect the Erlenmeyer flask to the graduated cylinder and collect the gas being produced into the graduated cylinder.Record the volume of gas that has been produced after the chemical reaction is complete.Lastly, weight the remaining mass of the Erlenmeyer flask after completion of the reaction.
Repeat all steps from 5-12 with three trials for each level. The Sodium Bicarbonate staying at a constant 1 mL with the acetic acid increasing by 0.5 for each level.
(0.5mL, 1 mL,1.5mL,2mL,2.5mL) When completion of the collection of raw data is reached, calculate the average being produced for each trial and convert it into moles using this formula. Moles of CO2=Vol of CO2 collected22400cm3