Materials Included In Kit

Additional Materials Required

Prelab Preparation

1. Photocopy enough Ion Formula Chart handouts for each group.
2. To save time, before collecting data during the class’s competition, the instructor can premeasure canisters of 15 mL of vinegar.
3. Also, instructors can measure the sodium bicarbonate before each competition launch. Another option is to have the groups pre-weigh their two sodium bicarbonate trial masses. Masses should be verified before launch.

Safety Precautions

Sodium bicarbonate may be harmful if swallowed. Wear chemical splash goggles, chemical-resistant gloves and a chemicalresistant apron. Remind students to wash their hands thoroughly with soap and water before leaving the laboratory. Please review current Safety Data Sheets for additional, safety, handling and disposal information.

Disposal

Please consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures, and review all federal, state and local regulations that may apply, before proceeding. Sodium bicarbonate may be disposed of according to Flinn Suggested Disposal Method #26a. Vinegar may be disposed of according to Flinn Suggested Disposal Method #26b.

Lab Hints

• Enough materials are provided in this kit for 30 students working in pairs or for 15 groups of students. Both parts of this laboratory activity can reasonably be completed in two to three 50-minute class periods.
• Enough materials are provided for each group to perform six launches (four testing and two competitive launches).
• Remind students to set aside enough of the baking soda for the two competition launches.
• Lens paper is included, if students would like to make a sodium bicarbonate pouch. Tissue paper may also be used to create a pouch (the pouch is not included in the weight of sodium bicarbonate or the weight of the rocket).
• Paper clips may be used to increase the rocket weight and the rocket mass/sodium bicarbonate ratio.
• Students may decorate the rocket with markers.

Teacher Tips

• This is a great end-of-year review activity. Students are required to combine their knowledge of formulas, chemical reactions, stoichiometry and Newton’s laws of motion, all in a fun engaging activity.
• For an extension activity, students can also graph various collected data. For example, Mass of Baking Soda Used vs. Time of Rocket Launch.
• Another option is to have students collect data with tablets or phones. They can take video and pictures when the rockets are launched and attempt capturing the rocket that flies the highest.
• Another fun activity involving stoichiometry and limiting reactants, is the Micro Mole Rockets—Hydrogen and Oxygen Mole Ratio—Student Laboratory Kit (Flinn Catalog No. AP6374).

Answers to Prelab Questions

1. Given 5.00 g of copper(II) chloride and 5.00 g of aluminum, how many moles of copper solid will be produced? Which reactant is limiting, copper(II) chloride or aluminum solid?

   3CuCl₂(aq) + 2Al(s) → 2AlCl₃(aq) + 3Cu(s)

   {14069_PreLabAnswers_Equation_7}

   Copper(II) chloride would be limiting. Only 0.04 mol of Cu will be produced.

2. The chemical names of the reactants are acetic acid and sodium bicarbonate. Translate the names of these two reactants into formulas. Write the two formulas below:
   {14069_PreLabAnswers_Equation_8}
3. Given the Law of Conservation of Mass tells us that mass is neither created nor destroyed, list the elements that must be present in the products from the reaction of acetic acid and sodium bicarbonate.

   Na, H, C, O

4. Using a list of common ions, brainstorm ten possible products that could be produced from Questions 2 and 3. Record each compound’s formula and name in Table 1. Use each element from Question 3 at least twice.
5. In Table 1, mark the top four most likely product compounds of acetic acid and sodium bicarbonate.

   Table 1.

   {14069_PreLabAnswers_Table_2}

Sample Data

Data Table B1. Group’s Launch Class Data

Data Table B2. Raw Data from Class Testing

Answers to Questions

1. What was the winning group’s ratio? Are there other features of the winning rocket that may have contributed to their success?

   The winning ratio was 150:1, by Group 6. The rocket’s weight to baking soda ratio was the highest one that cleared the one meter mark.

2. Using observations from lab and your answers in Table 1 from the Prelab Questions, what compounds are possible products of acetic acid and sodium bicarbonate? Why? What evidence supports your claims?

   A gas is produced during the reaction. From our prelab activity, two gases were listed. The gas could be carbon dioxide or carbon monoxide from the prelab. After launching, a liquid is also left over after the reaction. We listed several compounds in the prelab. This liquid could be water and another aqueous compound.

3. The reaction of acetic acid and sodium bicarbonate involves a double replacement that is immediately followed by the decomposition of an acid. Using your previous work, write the following chemical equations. Include states of matter (e.g., s for solids, aq for aqueous, l for liquids).
   1. Double Replacement:

      NaHCO₃(s) + HC₂H₃O₂(aq) → NaC₂H₃O₂(aq) +H₂CO₃(aq)

   2. Decomposition:

      H₂CO₃(aq) → H₂O(l) + CO₂(g)

   3. Overall:

      NaHCO₃(s) + HC₂H₃O₂(aq) → H₂O(l) + CO₂(g) + NaC₂H₃O₂(aq)

4. Vinegar is a solution of approximately 5% acetic acid in water. This is a volume percent (v/v) which means there are 5 mL of acetic acid per 100 mL of vinegar. The density of acetic acid is 1.05 g/mL. Use stoichiometry to determine how many grams of acetic acid are in 15.0 mL of vinegar.
   {14069_Answers_Equation_9}
5. What are the molar masses of the two reactants, acetic acid and sodium bicarbonate? Show all work.

   HC₂H₃O₂
   4(1.01 g/mol) + 2(12.01 g/mol) + 2(16.00 g/mol) = 60.06 g/mol
   
   NaHCO₃
   1(22.99 g/mol) + 1(1.01 g/mol) + 1(12.01 g/mol) + 3(16.00 g/mol) = 84.01 g/mol

6. Using stoichiometry, determine the amount of baking soda in grams needed to react with the grams of acetic acid in 15.0 mL of vinegar. Show all work.
   {14069_Answers_Equation_10}

   = 1.10 g sodium bicarbonate

7. Was the amount of baking soda your group used in the competition limiting, excess or the exact amount?

   The amount of baking soda used was limiting. Our group used 0.28 g in our first trial. To completely react the 15.0 mL of vinegar, 1.10 g of sodium bicarbonate would be needed.

   1. If the baking soda was limiting, how much more was needed to use up all of the acetic acid? Show your work.

      Since our amount was limiting, we would need to add 0.82 g of baking soda to completely use up the 15.0 mL of acetic acid (1.10–0.28 g = 0.82 g baking soda).

   2. If the baking soda was excess, how many grams were in excess? Show your work.
8. Some groups were able to be successful, even though baking soda was limiting. Why would this occur?

   Even though all the acetic acid was not reacted, enough carbon dioxide was produced to lift the rocket.

Teacher Handouts

14069_Teacher1.pdf

References

Special thanks to Deborah Maloney, Hollis Brookline High School, Hollis, NH, for providing the idea and the instructions for this activity to Flinn Scientific.

Introduction

Design and launch a film canister rocket that will fly at least one meter into the air, using a specific ratio of reactants as fuel! Combine your knowledge of chemical reactions, stoichiometry and the law of conservation of mass to create and analyze your very own rocket!

Concepts

• Chemical reactions
• Stoichiometry
• Newton’s laws of motion
• Law of Conservation of Mass

Background

Newton’s third law of motion states that for every action force there is an equal and opposite reaction force. Rockets clearly show Newton’s third law in action. When a rocket burns fuel, hot gases are forced out the bottom of the rocket at high speed. The fast-moving gas particles are pushed by the rocket chamber in one direction and the gas particles, in turn, push on the rocket in the opposite direction. This creates a net force that thrusts the rocket in the opposite direction of the ejected gases (see Figure 1).

In this lab, the rocket will be propelled by a gas released from a chemical reaction. Chemical reactions are all around us; reactants are constantly being rearranged into new products. For many chemical reactions, clues to indicate that a reaction occurred can be observed. Such clues include production or absorption of heat, absorption or emission of light, production of a sound, a change of color, formation of a precipitate, or release of a gas. Some chemical reactions may exhibit only one of these clues, while other chemical reactions may reveal several clues. By looking for these clues, it can be determined whether a chemical reaction has occurred.

Using sodium bicarbonate (baking soda) and acetic acid (vinegar), a gas will be produced and the force will thrust the rocket in the opposite direction. In chemical reactions, mass is neither created nor destroyed. This is known as the Law of Conservation of Mass. Any chemical change involves the reorganization of atoms into one or more new substances. In a chemical equation, the number of atoms on the left of the arrow must equal the number of atoms on the right side of the arrow.

Balanced chemical reactions are used for stoichiometry. Stoichiometry is the branch of chemistry that deals with the numerical relationships and mathematical proportions of reactants and products in chemical reactions. Using stoichiometry, the limiting and excess reactants can be determined. The limiting reactant is the reagent used up in the reaction and on which the overall yield of the product depends. The excess reactant is the reactant that is not completely used up during the reaction. For example, look at the balanced reaction of hydrogen and oxygen below. If 10.0 g of H₂ are mixed with 10.0 g of O₂, which one will “run out” first and act as the limiting reactant? We must first determine the number of moles of each reactant that we are starting with using stoichiometry. Then we must determine which of these reactants limits the amount of product formed. Consider H₂ first. The 4.95 moles of H₂ could theoretically produce 4.95 moles of H₂O. This is determined by looking at the balanced chemical equation to determine the stoichiometric ratio, which in this case is two to two. That is, for every two moles of hydrogen that react, two moles of water can be generated.

Now consider O₂. The 0.313 mole of O₂ could theoretically produce 0.626 moles of H₂O. This is determined from the stoichiometric ratio, which in this case is one to two. That is, for every one mole of oxygen that reacts, two moles of water can be generated.

Therefore, if all of the H₂ reacted, 4.95 moles of H₂O could theoretically form while only 0.626 moles of H₂O could form from the available O₂. The O₂ is therefore the limiting reactant in this example since O₂ limits the amount of H₂O produced. The O₂ will “run out” first while some of the H2 will remain in excess.

In this lab, chemical reactions, stoichiometry and rockets are all combined to reinforce skills used throughout the school year.

Experiment Overview

The purpose of this lab is to create a rocket that will travel the distance of 1 meter or more using a film canister engine fueled with 15 mL of vinegar (acetic acid) and an amount of baking soda (sodium bicarbonate) that yields a ratio of rocket mass to baking soda mass equal to or greater than 20:1.

Objectives

1. To propel a paper rocket a vertical distance of one meter using a film canister engine fueled with 15 mL of vinegar and an amount of baking soda that yields a ratio of rocket mass to baking soda equal to or greater than 20:1 (For example, if one g of baking soda is chosen, then the rocket must weigh 20 g or more. Or if 0.5 g of baking soda is chosen, then the rocket must weigh 10 g or more).
2. To have the best ratio of all the groups that meet the one meter height requirement.

Materials

Prelab Questions

1. Given 5.00 g of copper(II) chloride and 5.00 g of aluminum, how many moles of copper solid will be produced? Which reactant is limiting, copper(II) chloride or aluminum solid?

   3CuCl₂(aq) + 2Al(s) → 2AlCl₃(aq) + 3Cu(s)

2. The chemical names of the reactants are acetic acid and sodium bicarbonate. Translate the names of these two reactants into formulas. Write the two formulas below:
   {14069_PreLab_Equation_6}
3. Given the Law of Conservation of Mass tells us that mass is neither created nor destroyed, list the elements that must be present in the products from the reaction of acetic acid and sodium bicarbonate.
4. Using a list of common ions, brainstorm ten possible products that could be produced from Questions 2 and 3. Record each compound’s formula and name in Table 1. Use each element from Question 3 at least twice.
5. In Table 1, mark the top four most likely product compounds of acetic acid and sodium bicarbonate.
   {14069_PreLab_Table_1}

Safety Precautions

Sodium bicarbonate may be harmful if swallowed. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron. Wash hands thoroughly with soap and water before leaving the laboratory. Please follow all laboratory safety guidelines.

Procedure

Part A. Creation and Testing of Group’s Rocket(s)

1. Plan and discuss rocket designs with your partner. Read all directions below before proceeding.
2. Create a rocket or rockets, using the materials provided by the instructor (Each group receives one manila folder, one canister with cap and 5 g of sodium bicarbonate).
3. Rockets must be made with the materials provided by the instructor and must be completed during class time only. It cannot be taken home.
4. No part of the canister may be attached to the rocket. It can be snug fitting, but the rocket, canister and cover must be handed in separately for the competition.
5. When weighing the rocket, the rocket mass is only the mass of the rocket created in class. The canister, cover and fuel are not part of the rocket mass.
6. All tests and launches need 15 mL of vinegar. The amount of vinegar will be constant for all launches. Up to four testing trials may be run with 15 mL each (60 mL vinegar total is allocated for testing).
7. The 5 g of sodium bicarbonate are needed for the testing trials and two trials for the competition. Make sure to save enough sodium bicarbonate for the two competition launches.
8. When the group is ready to test rockets, the canisters must be launched from a sink or a large tray set on the floor. Every test must be announced. Shout “Fire in the hole” as soon as the canister is capped to alert the class of the impending explosion.
9. Record all test results and observations on the Rockets, Reactions and Ratios worksheet in Data Table A1 (e.g. mass of baking soda, the time it takes to pop, if it clears a meter).
10. When the testing is finished and the group has decided on the final launch details, fill out Data Table A2. Turn in the worksheet, completed rocket, and film canister with lid to the instructor.

Part B. Testing the Rockets—Class Competition

1. Each group will have two attempts to clear the meter mark. There may be two attempts with the same rocket design or one attempt each of two different designs.
2. Also, each group will be allowed a maximum of two minutes to complete each attempt. Timing begins when the baking soda and vinegar are mixed.
3. The instructor will provide the 15 mL of vinegar per attempt.
4. Each group will measure the amount of baking soda specified on the worksheet for the competition. The teacher will verify the mass before launching.
5. Members of your group are responsible for the launching of the rocket.
6. Members of the audience will verify if the entire rocket clears the meter. Video and photo finishes can be used as acceptable proof.
7. Record your trial data in Data Table B1.
8. Record the class trials in Data Table B2.

Student Worksheet PDF

14069_Student1.pdf