Consumable: Solid NaHCO3. They could not rely on prior knowledge alone simply because they lacked sufficient prior knowledge that would allow them to know what the products should be without even performing the investigation. Guarantees that a business meets BBB accreditation standards in the US and Canada. Get your online template and fill it in using progressive features. 1 Argument-Driven Inquiry in Chemistry. Ask students about baking soda: - Sodium bicarbonate is baking soda. Tell students that they should try to get the foam to stop as close as possible to the top of the cylinder without overflowing. Students will be able to explain that for a chemical reaction to take place, the bonds between atoms in the reactants are broken, the atoms rearrange, and new bonds between the atoms are formed to make the products. Why, on the molecular level, does changing the amount of baking soda or vinegar affect the amount of carbon dioxide gas produced? Did each group use similar amounts of baking soda and vinegar? I also included it in the Supporting Information below. Option 4: NaHCO3 (s) à NaH (s) + CO (g) + O2 (g). Sometimes it is hard to reduce, let alone eliminate, previous conceptions and biases when asking students to develop an argument from evidence. There are various choices for receiving the doc.
The vinegar is poured in afterwards to cause better mixing of reactants. Next, it's time to repeat the experiment, but this time we'll use 0. Could you just keep adding more and more baking soda to the same amount of vinegar to get more carbon dioxide? Bubbles will form and rise up in the cup. Graduated cylinder (100 mL). Students should consider these amounts as they plan how much of each reactant they will use as they start their trials. If there's one thing virtually all chemistry teachers can agree on, it's that stoichiometry is a difficult topic for students. Engineers must be able to ask probing questions in order to define an engineering problem.
Preview of sample stoich lab answer key. Remind students that in the last lesson, they learned that in a chemical reaction, certain atoms in the reactant molecules unbond from one another and then rearrange and rebond in different ways to form the products. Atomic weights are found below the element symbol on the periodic table. Tell students that an Alka-Seltzer tablet contains aspirin, sodium bicarbonate, and citric acid. Dioxide gas in Experiment #2. Vinegar and baking soda stoichiometry lab. Test it again for condensation with the dry inverted test tube. Once they establish a baseline pressure, students should add the citric acid and quickly stopper the bottle. While most groups executed the experiment without major flaws, I was reminded of the importance in giving them experiences that provide opportunities for failure and reflection in the lab. The appearance of condensation in the dry test tube is a sign that there is still some water left in your sample test tube. Maybe you spilled some as you put it in the crucible. What they did not consider was that the contents of their test tube were going to still be really hot.
Though I demonstrated some basic safety tips, how to set up their apparatus, and the general approach to performing the reaction, the bulk of the experimental design was going to be on them. Students will analyze the outcome and compare the presence of the gases in the container and make determinations about the densities of each. Make sure each test tube is clean and dry before you put it away. As a demonstration, combine vinegar, detergent, and baking soda in a graduated cylinder so that foam rises and spills over the top. Select Done in the top right corne to save the file. I had mentioned that one of the characteristics I liked about this lab was the student involvement in experimental design. 2) Application of stoichiometry. Holding the test tube by the clamp, move the test tube slowly back and forth through the flame. Conservation of Matter, Chemical Change, Photosynthesis, Balancing Equations, Reversible Reactions, Molecular Formula, Molecular Structure, Conservation of Mass, Interdisciplinary, Matter, Elements, Monomer | Elementary School. At the same time, their lack of knowledge prevents them from confidently knowing the correct reaction prior to investigation. I did not tell them how long to heat their sample or what to look for when determining if the reaction is complete.
Analyzing data in 9–12 builds on K–8 and progresses to introducing more detailed statistical analysis, the comparison of data sets for consistency, and the use of models to generate and analyze data. Place about 2 teaspoons of baking soda in a small cup for each group. Something funny starts to happen when 0. Every test should be conducted the same way. Allow the HCl solution to run down the inside wall of the test tube. If you take the first route, I'm sure we can come up with some convincing explanations. In this lab, students will conduct a chemical reaction that will be used to launch a rocket.
When trying to explain how their percent yield was over 100%, several groups initially struggled to realize they had just simply stopped the reaction too soon. They can be driven by curiosity about the world (e. g., Why is the sky blue? Just writing those sentences helps me understand why students struggle! Chemical Change, Pressure, Reaction Rate, Acid Base Reactions, Chemical Change, Conservation of Matter | Elementary School, Middle School. Use mathematical representations of phenomena to support claims. When a drop of HCl produces no additional CO2 bubbles, the reaction is complete and no more HCl should be added.
Pass the test tube through the flame until all of the water has evaporated. Students saw that the same type and number of atoms were in the reactants as were in the products. Heat your sample again for a few minutes. However, since each reaction appears equally plausible from the perspective of the student, this meant the evidence gathered was the primary driver behind the construction of their argument. Some students will realize that the later trials did not produce proportionally higher changes in pressure because there was not enough sodium bicarbonate to react with all of the citric acid. They will also be able to explain that the equal number of atoms on each side of the equation shows that mass is conserved during a chemical reaction. In this lab, students will have the opportunity to construct a rocket, with the challenges of both designing it and preparing a chemical reaction for its "fuel" in order to propel the rocket over the furthest distance. 3) Application of qualitative evidence. So now you're faced with a decision.
Use a model to predict the relationships between systems or between components of a system. Mass is conserved in a chemical reaction. Look at the chemical equation. You might recognize this reaction as the same one that you used to prepare carbon. Can two or more ideas be combined to produce a better solution? Also be sure that they see that there is an equal number of each type on both sides of the equation. 3 carbon atoms, 5 hydrogen atoms, 5 oxygen atoms, and 1 sodium atom. Let students know that although the reaction in this lesson looks more complicated, these same principles still apply.