JonathanBennettMrs.TincknellBiologyHonors12/14/17ScienceFair EssayExploring Chemical Combustion Gasoline, alcohol, and acetone areliquids that are used every day as fuel and first aid, as well as powerfulsolvents and cleaners. Gasoline is an efficient fuel used by many people everyday.
Alcohol has several uses, including cleaners, fuel, and first aid, as ithas powerful cleansing properties. Acetone, too, has numerous uses, serving asa solvent and fuel and cosmetic additive. Each liquid has many uses, and each ishighly flammable.
Of the three, gasoline will burn the longest. If ameasurement of gasoline were to be lit, it will burn longer and moreefficiently than the same measurement of alcohol or acetone because of its easeof combustion and its efficiency as fuel. The purpose of the followingdescribed series of experiment is to answer two main questions, the first being”Which chemical substance burns for the longest amount of time?”, and thesecond being “Which chemical substance burns the cleanest?” This experiment isset out to answer these questions because their answers may provide valuableinformation that can help benefit society, as well as provide a betterunderstanding of each substance and how each one reacts and combusts. To answerthese questions, a set of controlled experiments is held. The experiments arecontrolled as they are held under the same conditions with only one variable:the chemical substance that is being burned. The purpose of this experiment isto discover which substance burns the longest and which substance burns thecleanest, the answers of which can hopefully lead to a better understanding ofeach substance and of how each can benefit society.
Before discussing the experimentsthemselves, understanding of each substance must be established. Gasoline is asubstance made from crude oil, a fossil fuel. Fossil fuels are buriedcombustible geological deposits of organic materials, formed from decayedplants and animals that have been converted to crude oil, coal, natural gas, orheavy oils by exposure to heat and pressure in the earth’s crust over thousandsof years (ScienceDaily). The crude oil pumped out of the ground is calledpetroleum, which is an oily, thick, flammable, usually dark-colored liquid thatis a form of bitumen or a mixture of various hydrocarbons, occurring naturallyin various parts of the world and commonly obtained by drilling (Brain,Marshall; Dictionary.com). Petroleum liquid contains hydrocarbons, meaning thatit contains organic chemical compounds composed only of the elements carbon (C)and hydrogen (H) (Brain, Marshall; Carey, Francis). Chains of these hydrocarbonmolecules can form into a wide variety of products.
“For example, a chain withjust one carbon atom in it (CH4) is the lightest chain, known as methane. Asthe chain gets longer, they get heavier” (Brain, Marshall). Hydrocarbon chainsof five to seven carbons form solvents, including dry cleaning fluids and paintsolvents, such as acetone (Wonderopolis.org). The gasoline used for automobilefuel is made up mainly of hydrocarbon chains with seven to eleven carbon atoms.
These hydrocarbon molecules can combust. “Hydrocarbon combustion refers to thetype of reaction where a hydrocarbon reacts with oxygen to create carbondioxide, water, and heat” (energyeducation.ca). Energy is released from thesetypes of reactions. This energy is what powers the gas engine, which in turn,power the automobile (energyeducation.ca).
Gasoline is a substance made fromcrude oil, or petroleum, which is a highly flammable substance made ofhydrocarbons that combust and react with oxygen to generate energy that powersthe device of which it serves as fuel to. Isopropyl Alcohol, also known asPropanol or Isopropanol, is a colorless, flammable, water-soluble liquidproduced usually by methods of hydration (Dictionary.com; Favors, LaTasha). Theprocess of creating isopropyl alcohol begins with the process of Hydration.
“During hydration, the component substances of water, which are hydrogen andoxygen (H20), react with those that compose propene—carbon and hydrogen (C3H6)”(Favors, LaTasha). There are two methods of hydration under which isopropylalcohol can be produced. These methods include direct hydration and indirecthydration. “In direct hydration, propene and water are combined either in theirliquid or gaseous forms. For a reaction to occur, a solid acidic catalyst (asubstance that triggers chemical reactions) must be present when the twosubstances mix” (Favors, LaTasha).
Manufacturers use furnaces to apply pressureand heat to the material, to stimulate the reaction. However, as “not allmaterials are consumed in the reaction, a system for separating and recyclingwaste materials and byproducts is then employed” to ensure that the alcohol isas pure as it can be” (Favors, LaTasha). The second method of hydration isindirect hydration. “In indirect hydration, the propene is initially mixed anddissolved with sulfuric acid, in an apparatus called an absorber. The result isa mixture of sulfate ester” (Favors, LaTasha). Later in the process, thesulfate esters mix with water and run through hydrolyzers, which are machinesthat “break down the water and other complex molecules to create isopropylalcohol,” and, as with direct hydration, “byproducts are either recirculated orset aside” (Favors, LaTasha). These reactions form new chemical bonds andcreate isopropyl alcohol.
However, these chemical reactions often leave additionalbyproducts. The initial result of these reactions is a mixture of alcohol andvarious other wastes and byproducts. Thus, the substance is refined by theprocess of distillation, which is defined as “the volatilization or evaporationand subsequent condensation of a liquid” (Favors, LaTasha; Dictionary.com). Theprocess of distillation then produces one-hundred percent isopropyl alcohol(Favors, LaTasha). Isopropyl alcohol is a flammable liquid that is produced by athree-part process of hydration, hydrolysis, and distillation. Understanding the chemical structure ofisopropyl alcohol can help to also understand why the substance is so useful.
Thechemical formula of isopropyl alcohol is written as C3H8O, meaning that thereare three carbon (C) atoms, eights hydrogen (H) atoms, and one oxygen (O) atomper molecule of the liquid. “The three carbon atoms of isopropyl alcohol arebonded together in a three-carbon chain. The two carbon atoms at each end havethree hydrogen atoms bonded to them, and the carbon atom in the middle has onehydrogen atom bonded to it and one hydroxyl (OH) group bonded to it”(Study.com). Because of its hydroxyl group, isopropyl alcohol molecules areheld together only by weak hydrogen bonds. “Consequently, it has a much higherboiling point and melting point than propane,” another chemical substance withthe same number of carbon atoms and hydrogen atoms (Brennan, John). Also, asisopropyl molecules are only loosely held together, they can combust easily.
“Combustionis a process in which strong electrostatic force of attraction between themolecules are broken and simpler compounds are formed, resulting in the releaseof energy” (Jha, Amrendra). This is also why the substance is flammable,because the easily triggered combustion process takes the form of burning.Furthermore, Isopropyl alcohol is a very useful substance that can be used fora wide variety of products. For example, “exposure to oxidizing agents likechromic acid will convert isopropyl alcohol into acetone, while exposure toheat and concentrated sulfuric acid can dehydrate isopropyl alcohol to formpropene” (Brennan, John). When mixed with water, isopropyl alcohol makes for avery good disinfectant for surfaces, as well as an effective antiseptic forwounds. Isopropyl Alcohol is a flammable, water-soluble liquid made by one oftwo forms of hydration, and is very combustible, making it a very useful liquidused in first aid, cleaners, and even fuel.
Acetone is a colorless, volatile,water-soluble, flammable liquid usually derived by oxidation of isopropylalcohol or by bacterial fermentation of carbohydrates (Dictionary.com). Themolecules that make up acetone are composed of three atoms of carbon (C), sixatoms of hydrogen (H), and one atom of oxygen (O), making its chemical formulaC3H6O, a formula very similar to that of isopropyl alcohol, which is C3H8O.
Because carbon atoms are present in acetone’s chemical formula, acetone isconsidered an organic compound. Furthermore, “acetone falls under theclassification of ketones, which are organic compounds containing a carbonylgroup, where carbon and oxygen are bonded to each other with a double bond” (Study.com).Acetone is known as the simplest ketone, as it has the most basic structure ofthese bonds (Study.com). Acetone, known also as propanone, is produced inmultiple ways, including by the oxidation of isopropyl alcohol.
As wasmentioned before, isopropyl alcohol will convert into acetone from exposure tooxidizing agents, such as chromic acid. Such oxidizing agents react with thesubstance in such a way that it actually changes into a new substance, that is,acetone (Brennan, John). Another way that acetone is produced is by bacterialfermentation, also known as acetone-butanol-ethanol (ABE) fermentation. In thisprocess, acetone and butanol are produced from glucose using strands ofClostridia, which are strictly anaerobic bacteria. ABE fermentation producessolvents in a ratio of three parts acetone, six parts butanol to one partethanol (Nujum, Noufal). Finally, acetone hasmultiple uses, serving mainly as a cleaner or solvent. Acetone is an activeingredient in many nail polish removers because of its powerful ability toremove material. Because of this ability as well, it is used in paint removingliquids for automobiles and furniture, too.
It is widely used in the textileindustry for degreasing wool and degumming silk (ChemicalSafetyFacts.org). Acetoneis used in many products, though most all of these products utilize thepowerful ability it has as a solvent. Acetone is a flammable, water-solubleliquid, produced by the oxidation of isopropyl alcohol or ABE fermentation, andhas a powerful ability as a solvent. As each substance to be used in theexperiments has been clearly defined and explained, the steps for theexperiment may now be listed and understood. As was mentioned before, thepurpose of this experiment is to answer two questions, the two being “Whichchemical substance burns for the longest amount of time?” and “Which chemicalsubstance burns the cleanest?” Thus, to ensure the most accurate data possible,a set of controlled experiments are held. Some items were purchased beforehandin preparation for the experiments.
Three of the same sized metal bowls, astandard plastic barbeque lighter, metal measuring spoons (metal so that thechemical substances, especially acetone, would not melt or damage the spoons),and a stopwatch are included among these pre-purchased items. The experimentwas held in an outdoor patio at night, as night is the time of day where windis almost completely absent, and thus, cannot interfere with the results of theexperiment. Furthermore, each chemical was placed and ignited in the exact sameplace in the patio, to ensure a fair and equally consistent burn process foreach liquid.
After all the preparation is complete, it is time to begin theexperiment. This experiment is a controlled experiment,each step being carefully and meticulously completed. Each substance was heldin its own respective bowl, to ensure that the chemical substances do not mix. Furthermore,as the same fifteen-milliliter measuring spoon was used for each substance, itwas thoroughly washed after each time it was used to carry one of thesubstances. The experiment starts with measuring fifteen milliliters ofgasoline and pouring it into its corresponding metal bowl. The experiment wasoriginally completed by using only five milliliters of each chemical substanceinstead of fifteen, but the amount was changed so that the results would bemore accurate, as the larger the amount of each substance is used, the moreaccurate the results can be, and thus the amount was changed to fifteenmilliliters. After the substance is poured into its bowl, all other flammableliquids and materials are pushed far away, to guarantee that they do not catchfire. After all safety precautions are set in place, the substance is ignited.
The gasoline is ignited with a plastic barbeque lighter that carries butane asits fuel. The moment the gasoline ignites, the stopwatch is pressed, and thecombustion reaction is timed. When gasoline is first ignited, there is nolargely noticeable difference in the atmosphere.
however, after just a fewseconds, it begins to give off black smoke, as well as an offensive odor. Afterprolonged exposure to these, one might begin to experience discomfort in theireyes and lungs, which is why it is important to wear proper safety equipment,such as safety glasses and a respirator, as protection from the smoke. Just asa larger amount of each substance can increase the accuracy of the results, themore times an experiment is held, the more accurate the results will be. Thus,each substance was tested five times, of which the middle three results areincluded in the end results of the experiment. After being tested five times,the middle three results for gasoline came to be two minutes and eight pointtwenty-six seconds (128.26 seconds), two minutes and sixteen point zero fourseconds (136.
04 seconds), and two minutes and thirty-three point seventy-sixseconds (153.76 seconds), averaging to about 139.35 seconds.After experimentation with gasoline iscompleted, it is time to move on to the next substance: isopropyl alcohol.
Theisopropyl alcohol used in this experiment is ninety-two percent isopropylalcohol, meaning eight percent of it is water and the rest of it is alcohol. Experimentationwith isopropyl alcohol is done in the same way as was gasoline, only it is donein a new, clean bowl and with a different substance, that is, isopropylalcohol. As was done with gasoline, the isopropyl alcohol is ignited at thesame time the stopwatch is pressed. Unlike the gasoline, the isopropyl alcohollets off no smoke or offensive fumes whatsoever. It does give off an odor, butit is barely noticeable and is not offensive at all. The substance burnscleanly, but the flame is much smaller and less prominent than that of thegasoline. The end results of experimenting with isopropyl alcohol are threeminutes and twenty-seven point ninety-eight seconds (207.
98 seconds), threeminutes and thirty-eight point eighty-five seconds (218.85 seconds), and threeminutes and eleven point sixteen seconds (191.16 seconds), averaging to about 206.00seconds.Finally, the last substance to be tested isacetone. Just as before, the acetone is tested in the same way the othersubstances before it were, only in a new, clean bowl. As acetone evaporatesquickly, once it is poured into the bowl, it must be ignited quickly to obtainconsistent results. The acetone is ignited, and, at the same time, thestopwatch is pressed.
The acetone did not burn as dirtily as the gasoline, butalso not as cleanly as the alcohol. It was somewhere between the two. Theburning acetone did release some fumes, but they were mild and very tolerable.When the final experiment with acetone was completed, the middle three resultsended up being one minute and forty-nine point ninety-eight seconds (109.
98seconds), one minute and forty-four point sixty-seven seconds (104.67 seconds),and two minutes and two point twelve seconds (122.12 seconds), averaging toabout 112.26 seconds, making it the shortest lasting burn time of all theothers.
In conclusion, the final results of theseexperiments show that gasoline is not the longest burning, nor the cleanestburning substance among the ones tested. It showed to be only the secondlongest burning and it was the only substance to produce black smoke. Acetone,which was tested last, burned cleanly, but lasted for the shortest amount oftime. Isopropyl alcohol, which was tested second, burned the longest and thecleanest, releasing no smoke or harsh odors. These results show that theoriginal hypothesis has been disproven and rejected completely.
A revisedhypothesis would be “if a measurement of alcohol were to be lit, it will burnlonger and more efficiently than the same measurement of gasoline or acetonebecause of its purity and ease of combustion.” Furthermore, the questions forwhich this experiment was held have been answered fully and with surety, andthe research and results derived from the processes of preparing for andcarrying out the experiment possess the capability of expanding one’sunderstanding of each substance and of combustion reactions, an understandingthat may help impact society for the better if he applies what he learns toscientific purposes. Such an understanding may be valuable to an engineer, abiotechnician, an automotive person, or even just a student, as they can eachhave a better understanding of the substances, of combustion reactions, and ofthe scientific process after completing this experiment. As far as improving theexperiment, the only practical thing would be to find a more accurate method ofmeasuring the liquids, as it is very easy to accidentally spill some liquidwhen handling a regular filled measuring spoon. Besides this, though, theexperiment method was practical and uses very common materials and substances.This experiment explored the chemical structures of three substances, as wellas tested how each one combusts, leading to a better understanding of eachsubstance and how they react, an understanding that, if applied correctly, canhelp greatly impact society for the better.