The Law of Conservation of Mass

To identify the parts of a chemical equation. Students need to identify subscribe pets, coefficients, reactants, products, chemical formulas, and chemical symbols 2. To appreciate that scientific discoveries are often the result of inquiry. 3. To distinguish between an element, a compound, and a mixture (and between heterogeneous and homogeneous mixtures) 4. To balance a chemical equation in order to prove that the Law of Conservation n of Mass works quantitatively as well as conceptually 5.To respect that chemicals can be both helpful and harmful safety must be a p rarity and the intention of scientists can play a large role in determining if chemicals do ended hurt or help humanity 6. To prove experimentally the Law of Conservation of Mass that matter is not car dated or destroyed in a chemical reaction Standards NJ CORE CURRICULUM (SCIENCE) STANDARD 5. 2 (science and society) All stud .NET will develop an understanding of how people of various cultures have control etude to the ad vancement of science and technology', and how major discoveries and even TTS have advanced science and technology.You can either print o t the story or tell the story in your own words. This lesson corresponds with slides 14 on the pop written presentation. Slide 4 contains a short video (approximately 5 minutes) in which h the work of Lavisher is discussed. Be sure to mention the connection between his scientist fix work and the necessity of the work for Paris at this time in history. Why did he begin this pr Eject? And similar questions can be used to place this work in its proper historical context. B. Introduce the law of conservation of mass experiment.Be sure to emphasis zee the purpose of the experiment, mainly, to serve as a comparison to the work of Lavisher. C. Students should perform the activity. You may want to have students perform ram part A in day 1 ND save part B for day 2 unless you have a nice block of time. D. Following the conclusion of parts A and B, as well as the conclusion queue's ins, discuss the conclusion questions. Specifically, spend time on number 7 and 8. Number 7 asks students to draw connections between Lavaliere's work and what they have done.Number r 8 asks students to brainstorm ideas for other law of conservation of mass experiments. This is is unification because students will be choosing one of these ideas and designing an experiment lat err on. Lesson 2 Instructions for Teachers: Tell the story of Lavaliere's work with combustion. Make the connection bet en science and mathematics. Precise measurements were not common until Lavisher m dad them so. Observations, estimations, and generalizations were commonly found in ice once investigations.If you are planning on handing out the story rather than tell it be sure to explain what is meant by call. Powering slides 57 pertain to the connection between the law of conservation of mass and math, namely balancing equations. Slide 7 is a short video (approximately 5 minutes) in w hich balancing is explained as well as a short e explanation on naming compounds. Math teachers can teach balancing equations. This ca n be done in edition to the time that we spend balancing equations in science or the mat h teacher may take full responsibility for the balancing of equations. To further explain call a demonstration may be valuable. You can burn magma enemies and allow students to make observations, qualitatively and quantitatively. 2. First, introduce coefficients and subscripts and explain how they can help to s how us how the law of conservation of mass is present in every chemical reaction. Balance a simple equation, the formation of water is a good one to start with since most studs ants are familiar with the chemical formula for water.After 1 or more examples have students attempt to balance equations based on level of comfort with balancing. Have an answer key posted in the room so that students can see that they have correctly balanced the aqua actions. Ther e are many websites dedicated to balancing equations. I usually have my more am obvious students Google search a good site and write it on the whiteboard so that pee people who need extra practice or more of a challenge know where to go. 3. The selfsameness rubric can be completed by students at the end of this less son or at the end of this minutia. Suggest completing it at the end of the unit since you m y introduce more equations within the context of the lessons thus allowing students audit IANAL opportunities to improve their understanding. Lesson 3 Instructions for Teachers Begin this lesson by telling the story of Lavaliere's role in discovering oxygen. Be sure to mention the role played by Joseph Priestley. This is a good opportunity to disc us how technology, or the lack of technology played a role in the dispute regarding car edit for the discovery.Language barriers, difficulty in traveling far distances, and slow communication definitely played a role. Slides 810 should a ccompany this less son. Slide 10 contains a short video narrated by Bill Nee in which he discusses, with a m ember of the Chemical Heritage Foundation, the story of the work of Lavisher and his role discovering oxygen. Joseph Priestley role in this discovery is also mentioned. Have students refer back to our first law of conservation of mass experiment, specifically conclusion question number 8.Students will now decide on a scientific quests on that relates to the law of conservation of mass and design a controlled experiment in which they attempt to explain data and confirm or refute a hypothesis on the basis of this data. I live that students should be encouraged to choose a question that allows for a lengthy study, requiring multiple measurements. This will reinforce the concepts pert air-ling to the law of conservation of mass and allow you, the teacher, to draw connections between the law and your other chemistry topics. The final activity is a reflection pertaining to a scienc e demonstration.The bur inning of paper ties in nicely with many aspects of Lavaliere's work. See the attachment and ask students to discuss, in words, the similarities, or differences that they notice. This can be completed in class or it can be a homework assignment. A homework assign meet may be more appropriate if you feel that students need time to review the story of the e law of conservation of mass that you have told. Towards this end it is also useful to post your notes of the story on your aboard or whatever form of communication you ha eve with students.While I have dedicated the story of Lavatories work to some of his experiment s there is another story that can be told. Lavisher, who founded a business whose prim responsibility was collection of taxes, was beheaded during the French Revolt Zion. This sad story can be told in science of course, or it can take place in humanities (h story) or in language arts (English). The stow of Lavisher can tie in to the American and F ranch Revolutions for history class. In English class it can be told within the scope of excerpts or entire books that tell stories relating to revolutions.An example might be while e reading Charles Dickens' A Tale of Two Cities. The language arts connections offers the teacher an opportunity to focus on the irony that with the beheading of Lavisher the Free inch people removed a person who had arguably helped them a great deal and who wool d most likely have made many more significant contributions to the life of Parisian. Background Information A: the Antoine Lavisher lived and worked in the 18 century, during the time of the French revolution (Grey, 1982).Lavisher is often referred to as the father of modern chemistry (Discovery Education, 2005). Lavaliere's first experiment to lead him toward the e discovery of the law of conservation of mass was part of an experiment to study the CLC manliness of the drinking water in Paris (Culled, 2005). Lavisher boiled drinking water. Acc ording to Culled (2005) the first part of this experiment involved cleaning a glass flask, drying it, and then carefully weighing it. Next, a precisely assured sample of water was poured into the flask and for 101 straight day s heated.The water was heated so that it just reached the point of boiling. Eventually, solid sediment formed on the glass walls of the flask. Culled adds that after weighing the flash k Lavisher concluded that the weight of the flask, the water, and the solid sediment was exactly the same as the mass of the flask and the water with which he started this experiment. If anally, Lavisher removed the water and found that the mass of the water had not chi engaged. However, the mass of the flask and the solid sediment was equal to the mass of the origin anal clean flask.At this point in the experiment Culled (2005) tells us that Lavisher concluded t hat due to the longer exposure to high temperatures the flask some part of the flask muss t have turned into a new su bstance, although mass had not been lost. It is worth noting that in his time, many, if not all scientists believed that the e earth was comprised of the four elements of earth, fire, air, and water (Culled, 2005). Du ring the aforementioned experiment Lavisher wondered if water could be converted t o earth, which at the time, Culled states, included any solid substance.Because the mass oft he water in the experiment did not change Lavisher concluded that the answer was that no, water was not converted into earth. A less perceptive scientist would have concluded others sis due to the presence of the particulate. It was his attention to the mass and to exactness in measurement that allow De him to conclude that contrary to what others were espousing, the water did not Chain GE. Grey (1982) adds that the mass of the particulate was exactly equal to the mass that was missing when Lavisher measured the weight of the dried flask at the end of the 101 days.L bolster included that part of the glass flask had undergone a change due to constant t exposure to high temperatures. Grey adds that this experiment was also significant because SE it lead Lavisher to conclude that â€Å"just looking at an experiment wasn't enough to fin d out what was really going on† (p. 40). This experiment, notes Culled (2005) was significant n tot only because it lead Lavisher toward the law of conservation of mass but also beck cause lead Lavisher to the realization that precise measurements are critical in experiment notation, something that most scientists did not deem a necessity at the time.Many of Lavaliere's experiments, including the water experiment, involved co marring the weight of reactants to the weight of products. In other words, comparing the mass Of the substances he was experimenting with before a reaction to what he had after a reaction. Due to his emphasis on precise measurements Lavisher was able to show that the difference in weight between reactants and product s was always small (Culled, 2005).Whew n he initially started these experiments Lavisher was not certain if these tiny differences in mass were due to his inability to make more exact measurements or if matter was indeed bee g created or destroyed, a view that many scientists of the time thought was possible (Grey, 1982). Read about the science of alchemy if you are interested in how and why scientists o f the time believed that this was possible. It's worth noting that Lavisher was eventually able to conclude that matter is not able to be created or destroyed in part because he asked the question, a simple queue's n actually, concerning the missing mass.Grey, (1982) notes that â€Å"He believed there were lots of questions about the world all around him that needed answers. He wanted to look for things no one else had ever found† (p. 26). As we learn more regarding the stories be hind science discoveries, large and simple, we will notice that almost every one involves in acq uisitiveness on the part of the scientist followed by an experimental procedure designed t o answer the question, but it all starts with the question. Background Information B: Lavaliere's next area of interest was combustion.By the time Lavisher turned to the question of combustion he was well known for his emphasis on precise mess ornaments (Culled, 2005). This was helpful in experiments in which he was attempting to determine if mass had indeed been created, destroyed, or remained the same. Lavaliere's combustion experiments consisted of burning metals and compared weights of the metal s before and after heating (Mechanical, 2004). When Lavisher burned sulfur, tin, lead, and phosphorus he found that the m ass of the metal actually increased.However, he also found that when burned in a closed flask the mass of the air inside the flask decreased by the exact amount that the metal increased (G ere, 1982). When Lavisher heated the scales, metal bonded with air due to combustion) he f ound that air was given off as the mass of the metal decreased while the mass of the air in t e container increased by the same amount. Mathematics, which provides quantitative data, allowed Lavisher and later, tot her scientists, to prove that matter was not created or destroyed (Tab, 2004). The word co inspiration means that nothing has been lost.After Lavisher, scientists began to conclude e that in an isolated system (for example, a closed flask) mass is a constant (Johnson, 200 8). We know that a constant does not change. If we are able to find the mass of the â€Å"system m† before anything reacts we can compare it to the mass Of the System after the reaction and the difference should be zero, according to Lavisher. Johnson (2008) notes that Lavisher was the first to conclude that the total ma as of a system must be equal to the mass obtained in the beginning of the experiment, regard idles of changes in states of matter.Johnson adds that in France, the law of conservat ion of m ass is still known as Lavaliere's law. We will attempt to prove experiment with chemical r actions in an open system as well as a closed system and yes, we will use mathematics to a assist us in doing so! As scientists learned more about elements and compounds (again, thanks to Lavisher) they ere able to further explain, in more detail, what is indeed happening in chew magical reactions in terms of elements and compounds being rearranged. Today we know that this accounting is done through balanced equations.Balancing chemical equations is a techno queue employed by scientists in which simple, and sometimes complicated, mathematics IS use d to demonstrate the specific ratios of the substances involved in a chemical aqua Zion. We will also partake in the balancing Of equations and I think that you will find it inter sting to see that what Lavisher, the pioneer, first hypothesized over 200 years ago, because e he dared to ask a question, is now being analyzed and proven in our middle school science e class.Background Information C: Lavisher is credited with discovering the element oxygen. He arrived at the co inclusion that oxygen must exist as a result of his interest in combustion. Prior to Lavisher, scientists such as Joseph Priestly who was based in London, had found that when something burned, like metal, the weight of the metal call would be greater than the mass of the origin IANAL substance (Mechanical, 2004). This Priestley explained, was due to the presence of a most absence that was thought to be found in any substance that burns, called p Hollister (Grey, 1982).Scientists reasoned that the added mass (to the call') after something b runner was attributed to phlogiston. Grey notes that at this time scientists were aware that t the mass of the original piece of metal also decreased, which lead them to the conclusion, alb tit falsely, that phlogiston was transferred when something burns. While most scientists were satisfied with the explanation, others such as Olivia sire found a problem. When metals were burned the mass of the burned metal (called call ) actually increased (Mechanical, 2004).