The purpose of the Rocket Lab was to determine and calculate the best amount mixture of acetylene and oxygen gas in order to launch a rocket across the room successfully. During the rocket lab our goal was to understand the relationship between a balanced chemical equation and an ideal mixture of acetylene and oxygen gas needed for the most successful combustion reaction.
Method-Pipet Bulb/Rocket Calibration
For the Rocket Lab we used the bulb of a pipet as our rocket, along with acetylene gas and oxygen gas as our explosive reaction to successfully launch our rocket. To perform this lab the first thing we needed to do was measure the volume of our pipet in order to know our correct ratios of acetylene gas to oxygen gas later in our lab. We measured the volume of our pipet by first cutting the pipet approximately 3 mm under the bulb to get only the pipet bulb. After we cut the pipet we filled the pipet bulb with water and carefully moved the water from the pipet bulb into a 10mL graduated cylinder. Once we had the water from the pipet bulb in our graduated cylinder we read the amount of water that was transferred into our graduated cylinder (5.08mL) and that number told us the total volume of our pipet bulb. Once we had obtained the volume of our pipet bulb we began our lab.
Instrumental Set up
For the lab we retrieved a test tube rack and two test tubes in which we labeled one O2 (oxygen gas) and the other C2H2 (acetylene gas). We retrieved 2 single hole stoppers with plastic gas feeder tubes placed inside for our O2 and C2H2 test tubes and placed these fitted stoppers on our test tubes. (Do not press the stopper down too hard on the test tube or the test tube may break.) After we had our test tubes set up we took our pipet bulb and filled it up with water again. Once our pipet bulb was filled up with water we decided that for our first trial we wanted a 1:1 ratio of oxygen gas to acetylene gas. In order to find out at what point on the pipet bulb was half we divided our total volume by 2 (5.08mL/2=2.54mL), then removed that amount of water (2.54mL) into a graduated cylinder. Once the correct amount of water was removed we marked (in sharpee) the point on the bulb in which half the water was removed. Afterwards we filled our pipet bulb up with water till it was completely full again.
Launching the Rocket
Next, we removed the stopper from our O2 test tube and filled it up with ⅔ yeast solution, then added ⅙ Hydrogen Peroxide. After adding ⅙ Hydrogen peroxide we carefully placed the stopper back onto the test tube and quickly shook it allowing for the O2 reaction to take place. We filled our C2H2 test tube with ⅞ water and placed it back on the test tube rack with the stopper off. With all of our test tubes set up we took our pipet bulb and placed in onto the O2 stoppers gas feeder. We filled our pipet bulb up to our marked line with O2 gas and quickly took it off of the gas feeder and placed our thumb over the pipet bulbs opening to stop any gas from leaving the bulb. We then took the pipet bulb over to our C2H2 test tube and placed a pea size amount of solid calcium carbide into the C2H2 test tube that had previously been filled with ⅞ water. The reaction took place very quickly so we had to move fast. Once our solid calcium carbide was placed in the water we quickly placed our stopper with gas feeder on top of the test tube, placed our pipet bulb onto the gas feeder, allowed the rest of the bulb to be filled with acetylene gas, causing the rest of the water to drain out of the bulb, then took the pipet bulb off and covered the hole with our thumb very quickly again. Lastly, we took the pipet bulb over to our launch station, lit a match, removed our thumb and placed the match close to the end of the pipet bulb and observed the explosive reaction (if any) take place. We repeated this method to observe and record the outcome of a 1 O2 : 3 C2H2 ratio, 4 O2 : 1 C2H2 ratio, 1 O2 : 0 C2H2 ratio, and a 0 O2 : 1C2H2 ratio.
Short Answer Questions
In our Lab we learned the Law of Conservation of Mass, which is stated that in an ‘ordinary” chemical reaction, mass is neither created nor destroyed. Along with learning the Law of Conservation Mass we used Stoichiometry to balance our chemical equations in our pre lab. By having balanced equations we were able to see how many moles were used in the reaction to produce a certain outcome. We learned how to determine what are limiting reactant was in our ratios, and to physically see the limiting reactant by our rocket launching or not, and if it did how far based on each amount of oxygen gas and acetylene gas. Lastly, we learned the concept of a combustion. A combustion is defined as usually rapid chemical process that produces heat and usually light. By understanding this concept we were able to produce a combustion reaction between oxygen gas and acetylene gas to launch our pipet rocket. Based on our observations of the rocket lab, the best volume of ratio that produced the best results that we tested was a 1 O2 : 1C2H2 . No, this is not what I expected from the experiment.
With the balanced equation that we wrote during our pre-lab, the best volume ratio that would produce the best results would of been 2 C2H2 : 5 O2 . With this ratio we would of maximize the amount of acetylene gas and oxygen gas combusted with each other causing the highest and most effective explosive reaction. There were multiple errors that occurred during this experiment that we could improve to create a more effective experiment. First off, we did not test the 2 C2H2 : 5 O2ratio to see if that would of been the most effective explosive reaction. This should of been tested because it is the amount that balances the equation correctly and would of ideally produce the farthest rocket launch. This error took place because it did not cross me or my partners mind to use the 2:5 ratio. To minimize this error we can specify in our methods to test the 2:5 ratio.
Another error that occurred was having the flame burning right when our thumb was removed. I had to move the match slowly towards the end of the pipet bulb which could of resulted in too much gas escaping and changing the reaction which overall effects the distance traveled by the rocket. We could of minimized this problem by having a working lighter or a safe, constant flame, that would be used ignite the gas immediately after the thumb was removed. In our method we can help minimize this by specifying the importance of having a working lighter or tool that produces a safe, constant flame, so the gas is ignited right away. Lastly, our very last trial we had black soot in our pipet. Although we were testing a ration of 1:0, we should of retrieved a new pipet bulb, measured its volume, and used that because the black soot may of effected the reaction or weight of our pipet bulb, which results in incorrect data for our last trial. The black soot is formed by the combustion or separation of fuel during combustion, rising in fine particle.
The black soot produced in our pipet bulb was caused by the explosive reaction between the O2 and the C2H2 when ignited with a flame. In our methods we can state that if any black soot is produced, one must retrieve a new pipet bulb, find its volume, and use the new pipet for the rest of the trials in order to obtain correct and consistent data. In our Rocket Lab we had 2 successful launches at a 1:1 ratio. Our first successful launch went 421cm and our second launch went 70cm. The average of these two successful launches was 242.5 cm. Although we have zeros for the rest of our points, two of them were still successful but did not have any distance. Our 1:3 ratio launch produced black soot, and our 4:1 ratio launch backfired on us and blew a hole in our pipet.5. A new method that we could use to launch a rocket would be by using a film canister as our rocket bulb, and having our chemical reaction be between sodium bicarbonate (baking soda) reacted with acetic acid and water (vinegar). To try this experiment we would have too place one teaspoon of baking soda into a wax bowl, and then add ⅛ water to the baking soda and add that baking soda into the film canister. Once our baking soda is added to the film canister we would add vinegar until the vinegar fills to the top of the canister. Once our vinegar and baking soda is in the canister we would put the lid on the film canister, flip over the film canister, and allow the reaction to occur. This reaction taking place would produce water and carbon dioxide gas. This carbon dioxide gas builds up enough pressure inside the film canister causing it to escape through the bottom of the canister resulting in our rocket to launch. This chemical reaction would allow our rocket to go much farther because the reaction is taking place within the canister. In comparison to our rocket bulb, we would have a much higher concentration of gas coming out of our rocket resulting in a farther distance launched. 26. Fluorine may be a better oxidizer than oxygen because it is an extremely strong agent. The problem with fluorine is that it is so powerful that it is seen to be impractical because it causes more problems than it solves. Liquid fluorine has never been used as an oxidizer in an actual launch vehicle because it reacts with the materials you store it in.
It is said that the fluorine reacts with not only the walls but the fuel lines, pumps, and interior combustion chambers and the only way to keep the fluorine from reacting with the materials is by coating everything with the correct and right material. This process is much hard and takes away from the positive outcome fluorine could have on an actual launch vehicle. Conclusion In the Rocket Lab we had two successful trials with a measurable distance, but overall 4 successful combustion reactions.
Over the entire lab our most successful launch was our first trial, in which we had a 1 O2 : 1C2H2 ratio, and a total distance of 421cm. Our 4 O2 : 1 C2H2 ratio had potential to be very successful, but the combustion backfired and blew a hole through our pipet bulb. These launches showed us that if we worked with our ratios more and performed more trials we would find the most successful ratio that produces the most efficient combustion and shoot the rocket the farthest. To improve this experiment we should of tested a 2 C2H2 : 5 O2 ratio because this is the balanced form that should theoretically produce the best combustion. Also, we could of improved our experiment by having a constant flame to react faster, not a match.
Overall, we learned how to produce a combustion reaction by using O2 and C2H2 and an open flame. Lastly, we learned which ratio produced a combustion reaction efficient enough to launch our rocket, along with ratios that had no combustion reaction at all.