A Hydrogen Powered Bottle Rocket

Size: px

Start display at page:

Download "A Hydrogen Powered Bottle Rocket"

Bernard Daniels
6 years ago
Views:

A Hydrogen Powered Bottle Rocket Rockets are made by filling plastic water bottles with a mixture of hydrogen gas and oxygen gas. The rocket is launched by igniting the mixture with a flame.

1 A Hydrogen Powered Bottle Rocket Rockets are made by filling plastic water bottles with a mixture of hydrogen gas and oxygen gas. The rocket is launched by igniting the mixture with a flame. The bottle will fly several meters. The rocket will be launched from a short section of plastic pipe. Organization and Safety Concerns This activity requires quite a bit of preparation, and once your water bottles are filled with different ratios of hydrogen and oxygen gas. I will demonstrate how to launch your bottle. Students who may be alarmed by explosions should NOT light the rockets because a particularly loud explosion is likely to occur. Anyone close to the launch site should wear eye protection and ear protection or put there hands over their ears. Hydrochloric acid is corrosive. Hydrogen gas is explosive. Objectives: 1) Determine the ideal ratio of hydrogen to oxygen in our bottle rockets that will make the bottle fly the greatest distance from the energy from this reaction. 2) Practice naming the chemical compounds reacted and produced in the reactions that we are carrying out. 3) Practice: Using unit analysis determine the mass of a reactant (magnesium metal) needed to produce the required volume of a product (hydrogen gas). 4) Practice: Using unit analysis determine the volume of a reactant (3.0 molar hydrochloric acid) needed to produce the required volume of a product (hydrogen gas). 6) Practice making volume measurements. Materials and Chemical Reactions: Plastic pipe with a diameter larger than that of the plastic water bottles Eye protection for all students Ear protection for the person lighting the rockets Plastic water bottles (Dasani) for the combination reaction of hydrogen gas with oxygen gas: Reaction 1. H 2 (g) + O 2 (g) H 2 O (l) Large plastic container for filling bottles with gases over water Glass flask for hydrogen gas production by the single replacement reaction of hydrogen atoms from hydrochloric acid by magnesium metal: Reaction 2. HCl (aq) + Mg (s) MgCl 2 (aq) + H 2 (g) A hydrogen powered rocket 1 hydrogen_rockets_2018.odt

2 Materials:? ml of 3.0 Molar HCl (you need to calculate this volume) Magnesium ribbon (you need to calculate the amount) Electronic balance oxygen tank and regulator. 7.5 cm I.D. shipping tube or pipe Sodium carbonate for the double replacement reaction to neutralize any leftover hydrochloric acid after the reaction with magnesium: Reaction 3. Na 2 CO 3 (s) + HCl (aq) CO 2 (g) + H 2 O (l) + NaCl (aq) Butane Lighter to provide the energy with the combustion reaction to light the rockets: Reaction 4. C 4 H 10 (s) + O 2 (g) CO 2 (g) + H 2 O (l) Pre-lab Before you begin the lab, you and your group must have the following items complete in your lab journal: 1) Write balanced equations for the 4 chemical reactions that we will be performing in this lab. 2) Fill your bottle with water from the faucet up to the base of the neck. Pour the contents into the 500 ml graduated cylinder and record the volume of the bottle with the appropriate units and significant figures. Make 3 independent measurements of the volume of the bottle. 3) Make a table in your journal to record your data. Fill in your calculated amounts of all reactants and products see sample here: H 2 :O 2 ratio Grams Magnesium Volume 3.0 M Hydrochloric Acid Solution ml Hydrogen ml Oxygen Distance Bottle Traveled Groups 1H 2 :2O 2????? 1-3 Groups 1H 2 :1O 2????? 4-6 Groups 7-8 2H 2 :1O 2????? 4) Recreate and label the drawing of the setup for the single replacement reaction on the first page of this handout. 5) Calculate the volume of hydrochloric acid solution necessary for each trial in your journal. Fill the values in the table. (Show all your work!) 6) Calculate the mass of magnesium necessary for each trial in your journal. Fill the values in the table. (Show all your work!) 7) Mark your bottle from the bottom up at 1/3 volume (groups 1-3), 1/2 volume (groups 4-6) and 2/3 volume (groups 7-8) and label them with your names and period number. record the volumes of hydrogen and oxygen that your bottle will contain. 8) Write the procedure in your lab journal. 9) List the hazards and precautions that must be taken in this lab. A hydrogen powered rocket 2 hydrogen_rockets_2018.odt

3 Procedure: 1. Using the mass per unit length of the magnesium ribbon, calculate the length of magnesium ribbon required to produce your desired volume of hydrogen gas. Measure out the appropriate length of magnesium with a centimeter ruler. 2. Filling the bottles with hydrogen: Fill the flask with 100 ml of 3M hydrochloric acid at the fume hood. Report any spills. Put the flask in a 600 ml beaker that is about ¼ filled with tap water as a cooling bath. Prepare to drop your magnesium ribbon into the flask while stoppering it immediately so that you don't lose any gas. Have the rubber tube in the mouth of the bottle that has already been submerged in the water bath so that all of the gas produced goes into the bottle. Share this setup with the group at the adjacent table. You should be able to fill all of your bottles without having to add new hydrochloric acid to the flask. 3. Groups 1-3: Fill the bottle just over 1/3 full of hydrogen gas from the single replacement reaction flask and put the cap back on the bottle. Keep the bottle inverted (mouth downwards) at all times. Groups 4-6: Fill the bottle just over 1/2 full of hydrogen gas from the single replacement reaction flask and put the cap back on the bottle. Keep the bottle inverted (mouth downwards) at all times. Groups 7-8: Fill the bottle just over 2/3 full of hydrogen gas from the single replacement reaction flask and put the cap back on the bottle. Keep the bottle inverted (mouth downwards) at all times. 4. Go to the front of the room to fill the remainder of the bottle s volume with oxygen gas. Leave a little water in the neck of the bottle and keep the bottle inverted (upside down) to prevent any gas from leaking out until you light it. 5. After everyone has filled their bottles. Clean the single replacement reaction flask after discarding the leftover acid and magnesium chloride solution in the waste container marked acid in the hood. Observe what happens when the acid reacts with the sodium carbonate in the waste beaker. Record your observations. 6. Clean up and wait for all groups to catch up before we launch our rockets. 7. Launch and record distance data for all of the bottles. A hydrogen powered rocket 3 hydrogen_rockets_2018.odt

4 Write Up Questions for Hydrogen Rockets Answer the following questions individually. Responses can be hand written or word processed. They must be double spaced. This is an individual (not a group) assignment. 1. Create a scatter plot of the data on graph paper or use Logger Pro on a computer. Your group can create the scatter plot and print a copy for each member. (Excel file of data available in Read folder of Landreville shared files as well as on Schoology.) Graph the H 2 :0 2 ratio on the x-axis and the distance traveled on the y-axis. Do not connect the points. Scale and label your graph appropriately. Submit this graph with the responses to the other questions. 2. Does the graph support the claim that there is an optimum ratio of H 2 to 0 2 that will result in the longest flight by the rocket? Explain why or why not. What other variables need to be considered in this experiment? Give at least one other variable that affects the flight of the rockets. 3. Producing hydrogen gas to fuel your bottle rockets requires 2 chemical compounds, HCl and Mg. Which of these 2 reactants limits the amount of hydrogen that you can produce? You must include evidence (balanced equation, calculations, observations) to support your answer. 4. What did you learn from this lab? Give at least 2 things that you learned. This could include lab techniques, safety procedures, or understanding of chemistry. It can also include what you learned from the prelab. 5. Evaluate this lab. Include in your evaluation, any suggestions for changing procedures to improve the success of your rocket launches as well as a discussion of whether this is a worthwhile chemistry activity. A hydrogen powered rocket 4 hydrogen_rockets_2018.odt

5 Data: (You can dowload the Excel file of this data on Schoology in the Unit 5 folder) H2/O2 ratio Distance (m) A hydrogen powered rocket 5 hydrogen_rockets_2018.odt

6 A hydrogen powered rocket 6 hydrogen_rockets_2018.odt

7 A hydrogen powered rocket 7 hydrogen_rockets_2018.odt

8 Answers to Pre Lab Questions: 1. Reaction 1. 2H 2 (g) + O 2 (g) 2H 2 O (g) Reaction 2. 2HCl (aq) + Mg (s) MgCl2 (aq) + H 2 (g) Reaction 3. Na 2 CO 3 (s) + 2HCl (aq) H 2 CO 3 (aq) + 2NaCl (aq) Reaction 4. C 4 H 10 (s) + 6.5O 2 (g) 4CO2 (g) + 5H 2 O (g) 2. Volume of bottle ~ 633 ml +- 3 ml. (measured up to base of the neck) 3. Example calculations H 2 :O 2 Grams ratio Magnesium Groups 1-3 Groups 4-6 Groups See drawing Volume 3M Hydrochloric Acid Solution ml Hydrogen ml Oxygen Distance Bottle Traveled 1H 2 :2O 2.23 g 6.3 ml 211 ml 422 ml? 1H 2 :1O 2.34 g 9.4 ml 317 ml 316 ml? 2H 2 :1O 2.46 g 13.6 ml 422 ml 211 ml? 5, 6 See values on table for Mg and HCl amounts. 8, 9 Procedure and safety in your journal. Procedure Notes: Mass per unit length of magnesium ribbon:.021 g/cm A hydrogen powered rocket 8 hydrogen_rockets_2018.odt

9 A hydrogen powered rocket 9 hydrogen_rockets_2018.odt

EXPERIMENT. The Reaction of Magnesium with Hydrochloric Acid; The Molar Volume of Hydrogen

EXPERIMENT. The Reaction of Magnesium with Hydrochloric Acid; The Molar Volume of Hydrogen EXPERIMENT The Reaction of Magnesium with Hydrochloric Acid; The Molar Volume of Hydrogen PURPOSE In this experiment you will determine the volume of the hydrogen gas which is produced when a sample of