Decide on how much vinegar and baking soda you will use and write these amounts in the chart on the activity sheet. Do a demonstration using Alka-Seltzer or a similar effervescent tablet in water to show that citric acid reacts with sodium bicarbonate to produce carbon dioxide gas. Changing the amount of reactants affects the amount of products produced in a chemical reaction. Students will analyze the chemical equation for the reaction between vinegar (acetic acid solution) and baking soda (sodium bicarbonate). Students need to experience the fact that science is not just a linear process driven by knowing exactly what to do and exactly what to expect every step of the way without hiccups.
Select Done in the top right corne to save the file. As absurd as this seems to you and me, it seems plausible to many of them. How many of each type of atom is on the product side of the equation? Chemical Change, Chemical Change, Observations, Acid, Chemical Change | Elementary School. Reweigh each cool test tube and contents to the nearest hundredth of a gram (0. With respect to materials, I gave them the following list of equipment and the chemical they were going to consume. As a demonstration, combine vinegar and baking soda to show students the chemical reaction described in the equation. Atoms are not created or destroyed in a chemical reaction. Overall, the lab itself took anywhere from 20-30 minutes to set up and execute. Help students count the atoms in the reactants and in the products of the vinegar-baking soda reaction. You can use three options; typing, drawing, or capturing one. You may choose to limit students to a maximum of three tries or let them experiment further if time and supplies allow. Get, Create, Make and Sign lab 23 decomposition of baking soda stoichiometry answers. Since we were nearing the end of our stoichiometry unit, this was a perfect application.
Ensures that a website is free of malware attacks. The appearance of condensation in the dry test tube is a sign that there is still some water left in your sample test tube. This is a 3:1 ratio. Option 4: NaHCO3 (s) à NaH (s) + CO (g) + O2 (g). Using less baking soda, for instance, produces less carbon dioxide gas because there are fewer atoms from the baking soda to produce the carbon dioxide. Use professional pre-built templates to fill in and sign documents online faster. Give each Student an Activity Sheet. Note: It is not necessary for students at the middle school level to know which particular atom in the reactants ended up in which product. Fill in every fillable field.
All new trials should be conducted this same way. A balanced chemical equation shows that no atoms are destroyed and no new atoms are created in the chemical reaction. They know just enough to successfully accomplish their task, even if they do not immediately start making connections to content already learned. Can you add the baking soda first and then the vinegar on one trial and then switch it for the other trials? Dioxide gas in Experiment #2. Stoichiometry - No Limits to Limiting Reactants. It might seem strange, but sometimes a product can be made up of atoms from only one reactant. There's the reason for the 3:1 ratio of moles of sodium bicarbonate and citric acid! In this demonstration, students will see that different food dyes react with bleach at different rates. Editor's Note: Readers may be interested in reading a Pick about Argument-Driven Inquiry in Chemistry posted Chad Bridle.
Also, the baking soda should be added to the cylinder first. NSTA Press, 2015, pp. Make a detergent solution by adding 1 teaspoon of liquid dish detergent to 2 tablespoons of water. Three complete lessons: each lesson includes student notes, detailed teacher notes, check for understanding exit tickets, and homework. When a drop of HCl produces no additional CO2 bubbles, the reaction is complete and no more HCl should be added. Some groups only recorded the mass of their sodium bicarbonate, without considering the mass of their test tube and glass stir rod. The lab will culminate with a competition amongst students to see whose rocket will travel the longest distance. 3 carbon atoms, 5 hydrogen atoms, 5 oxygen atoms, and 1 sodium atom.
Do not point it at anyone or at yourself. You are going to perform a quantitative experiment to determine the mass of NaCl that can be produced (the actual yield) from a specific amount of NaHCO3. What do the little numbers below and to the right of each letter mean? As chemistry teachers, the depth of our content knowledge allows us to systematically rule out three of the reactions without even performing the experiment. If you take the first route, I'm sure we can come up with some convincing explanations. Sometimes it is hard to reduce, let alone eliminate, previous conceptions and biases when asking students to develop an argument from evidence. Keywords relevant to Lab 23 Decomposition Of Baking Soda Stoichiometry Answers. Turn on the Wizard mode on the top toolbar to get extra pieces of advice.
Point out that the type and number of atoms in the reactants and in the products are exactly the same. We had just finished our reactions unit, so they were all familiar with the generalized pattern that a decomposition reaction follows. What atoms is sodium bicarbonate made of? Scientific questions arise in a variety of ways. Then, when they use 40 mL of sodium bicarbonate solution for each trial, they can practice proportional reasoning to determine that there are 0. The molar mass (MM) of a compound is equal to the sum of the atomic weights of all of the atoms in the compound.
Engaging in argument from evidence in 9–12 builds on K–8 experiences and progresses to using appropriate and sufficient evidence and scientific reasoning to defend and critique claims and explanations about natural and designed worlds. When they were finished, each group was required to produce a whiteboard that resembled the following structure: Figure 2 - Whiteboard Template. Because of this, many of them remembered that they could identify the presence of CO2 and O2 based on what happened when a lit splint was placed into the test tube. A problem can involve writing chemical formulas, balancing equations, then multistep calculations converting amounts from grams to moles and back again. 2) Application of stoichiometry. They can graphically analyze this discrepant event by plotting the change in pressure vs. the mass of sodium bicarbonate and viewing all 5 of the data runs. I did not tell them how long to heat their sample or what to look for when determining if the reaction is complete. Materials for the Demonstration. Repeat steps 7 and 8 with test tubes 2 and 3. I also included it in the Supporting Information below. Their task: Figure out which balanced chemical equation accurately represents the decomposition of sodium bicarbonate.
30 grams of citric acid. 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. Once they establish a baseline pressure, students should add the citric acid and quickly stopper the bottle. To test that all of the water has been evaporated, remove test tube 1 from the flame and hold an inverted, clean dry test tube directly over its mouth. Follow the simple instructions below: The days of terrifying complicated legal and tax documents are over. Doing so resulted in a much higher product mass than they had predicted since there was still unreacted sodium bicarbonate in the test tube. Any time the reaction has something other than a 3:1 ratio of the reactants, one of the reactants limits the production of gas.
Graduated cylinder (100 mL). What are the constraints? Each group was given approximately 20 minutes to come up with an outline for their experimental design. Figure 3 - Hot samples melt plastic. Planning and carrying out investigations in 9-12 builds on K-8 experiences and progresses to include investigations that provide evidence for and test conceptual, mathematical, physical, and empirical models. Get access to thousands of forms. Students will see that the gas produced in the actual reaction is also written in the products of the equation.