Thomas Edisons contribution Essay Example | Topics and Well Written Essays - 750 words

Thomas Edisons commitment - Essay Example In 1979, Edison built up a carbon-fiber light. He exhibited activity of light at his Menlo Park research center. Exceptionally one year from now, he started delivering lights industrially in which he utilized carbonized bamboo as fibers. In the wake of finding that the oxygen debilitates the platinum once it gets warmed, he put the fiber in a vacuum bulb. This doubtlessly improved the exhibition of his light. The market was enthusiastically hanging tight for a gadget that could unravel their lighting needs. Edison applied the Joule's and Ohm's laws in growing high obstruction lights lessening the size of copper conduits and subsequently its expense. He was the primary individual to change over carbon into a wire-kind ; the innovation helped him to make radiant electric lights giving one greater utility that satisfied market needs (Inventions (2012).â â Electric Power SystemWhen question comes to creating electric force framework, he wanted to create host of different gadgets, for example, electrical generator, electric engines, wires to forestall over-burdening, and the screw attachment to hold lights. Edison additionally structured an immediate current framework that was required to give capacity to a segregated single structure. Before long he understood that a substituting current framework was a superior option for high-voltage transmission. He didn't build up a rotating current framework since he accepted that high voltages were perilous. His commitment to the improvement of electrical frameworks and gadgets is unprecedented.His just innovation in the field of unadulterated science came to be known as the Edison impact.

Dont Remove Huck-Finn! - Free Essay Example

Why would we remove a great American classic? We should not remove Huckleberry Finn. However, some people may believe that this novel causes way too many problems to still be available to read. This novel is one of the few books in American history that can relate to the situations that was going on when this book came out. Huckleberry Finn may have caused many problems ever since it has been having been published, but it causes problems because people that read it doesnt want to be outside of their comfort zone. This is the number one reason why people dont want this book to be available to the public. Huckleberry Finn teaches people about American history. It shows the readers how our country used to be. This story tells readers that we used to have slaves. At the beginning of this novel, Huck says Miss Watson has a big nigger named Jim. That was just the way of life back then, and people are offended by it. Mark Twain did not write this novel to cause controversies or to offend anyone. One of the main reasons he wrote this book is to show how the US used to be. This novel was also written to show the readers how a white boy and a black man can get along with all the things that were happening back then. Huck and Jims relationship grows very close together while they both are trying to get free. It started when Huck went into that town and spoke to a woman. The woman told Huck that people were after Jim, so Huck ran back and said: Come on Jim they are after us. Huck said us because he believed that they were like family and that their relationship grew so close with one another. Lastly, that Huckleberry Finn should not be removed is its just a good book to read. This book was written in the 1880s and its still a hot book. People love Huckleberry Finn, not because it has the n-word in it, but because it shows how whites and blacks can get alone. If people could get over the use of the n-word in this they would love it too. Huckleberry Finn is an awesome book for so many reasons, and it doesnt deserve to be taken away. Huckleberry Finn is an amazing book, and people should not have the right to take this book away. This book has so many details about how life was in the past. This book teaches our students how to embrace the past, and shows our students that it was the way of life. It shows how a white person and a black person can get along with all the problems that we had back in the day. This book is an awesome book and it shouldnt be getting taken away from the people that love this book.

Rampage A Movie about a Serial Killer - 2935 Words

Rampage is a 1993 movie about a serial killer whose motive is blood. On a December afternoon, Charles Reece buys a gun and murders three adults in their home. After shooting them to death, Reece mutilates the two women and drinks their blood. A day or two later, Reece kills a woman and her five year old son. After Reece mutilates and drinks the blood of the mother, he takes the child’s body which is later found. When caught by the police, Reece clearly presents signs of mental disturbances as he justifies his killings by saying that the people he killed were out to get him and that he needed blood to live. The main problem in the movie however is whether or not Reece will be found guilty and put to death for his crimes, found guilty and sent to a mental institution, or found not guilty by reason of insanity. Since Reece bought a gun before he killed the first three individuals, and the fact that he knew the mother and child that he killed, the prosecuting attorney tries to pro ve the Reece is in fact sane and just sick. On the other hand, the defense sheds light on Reece’s past at a mental hospital as well as his detachment from reality. After three more killings and a trial that brings up Reece’s cognitive and mental abilities as well as the premeditation that went into his killings, Reece is found guilty and sent to a mental institution. I chose this movie and this particular character for several reasons. For one, I am very interested in studying and learning aboutShow MoreRelated The Truth About Serial and Mass Murders Essay1033 Words   |  5 Pages A murderer is a murderer. There is no doubt about it, a person like that deserves to be punished for the crime they committed. However, not every killer is the same; there are some who are mass murderers who go on killing rampages for reasons of their own, and then there are the serial killers that love to kill people because it makes them feel some sort of emotion. People often mistake these killers as one and the same, but in reality they are completely different in the ways they are profiledRead More Natural Born Killers Essay1827 Words   |  8 Pagesclassic, Natural Born Killers, excited and traumatized its audiences while also causing controversy. The tale of white trash lovers caught up in a realm of chaos that includes a continuous murderous rampage from state to state, draws in audiences with its graphic violence and riveting pulse inducing music. Yet, the message of this film seems to be much deeper than just exposing audiences to yet another chaotic action movie filled wi th guns, blood and mayhem. Stone’s Natural Born Killers examines the subjectRead MoreThe Crimes of Andrei Romanovich Chikatilo1664 Words   |  7 PagesAndrei Romanovich Chikatilo seemed to be just like a regular man. He had a wife, two kids, was a teacher in Russian literature, an engineer, and a proud soviet party member. No one would have ever guessed he was one of the world’s most notorious serial killers. By day, he was your average Joe literature teacher, but by night he took upon a darker passion that involved rape and murder. He would lure his victims into decollate locations with sadistic intent unknown to them. Chikatilo managed see out hisRead MoreThe Opinion Of Journalists, Politicians, By Aileen Wournos2139 Words   |  9 Pagesdirector who produced two documentaries about Aileen, said, â€Å"The idea of a woman killing men – a man-hating lesbian prostitute who tarnished the reputations of all her victims – brought Aileen Wuornos a special kind of hatred.† Aileen was a murderer, a monster. Monsters do not have rhyme or reason to their actions, pasts that could ground them in humanity, or a place in society. However, others feel differently. A strange blend of victim and serial killer, many scholars are looking at the case ofRead MoreEssay about Mock Documentaries2177 Words   |  9 Pagesadults sent into the woods to make a movie of their adventure. This documentary style film takes place in Burkettesville, Maryland were a subsequent legendary haunted woods is the center of focus. Upon entering the old cemetery from the legend, strange events start to occur. They enter the forest and hear strange noises from the woods, get lost, lose their only map, they are soon starving, cold, bickering through the forest while videotaping the whole time. The movie is a documentary of their subsequentRead MoreCause Of School Shootings2045 Words   |  9 PagesColumbine, Colorado thirteen people died and twenty-four were in jured in one of the worst school shootings in America’s history. In this school massacre, there were two shooters by the names of Eric Harris and Dylan Klebold who died after their shooting rampage by suicide. Their original plan was to set off bombs during lunch where an estimated 500 people would’ve been during the time. The plan changed when the bombs did not detonate in time and that is when the two decided to open fire on the school. Harris

Essay on Feudalism and Capitalism - 3836 Words

Feudalism and Capitalism Economic processes are those involving the production and distribution of goods and services. However, they do not alone determine this production and distribution. There is an interrelationship of economic, cultural, environmental, and political processes that all help to shape each other. Nothing that we do can be defined as a single process, for it is the interaction itself that helps to produce the final results that we observe. To understand this more fully the following basic definitions may be of use: Cultural Processes are those that involve the creation and transfer of knowledge-the production of meaning. Political processes are those by which we establish and enforce rules, and they†¦show more content†¦Films are important and useful tools for the analytical process that needs to take place when searching for the answers to the questions. Films are understood to be, among other things, the product of a particular economic theory or set of theories (which can be contradictory), to teach particular theories (including economic theories), and to provide an objective for analysis using economic theory. (Professor Gabriel) It is with this in mind that the films of Matewan and Norma Rae are of importance to us when analyzing the concepts of feudalism and capitalism, because they are films that contain in them examples from these two types of economic systems. While the concept of unions is prevalent in both films, the reasons for their existence and the results of their existence appear to be quite different, but important all the same. Thus, the films can also be used to help increase our understanding of the importance and the role of unions in society. John Sayles, the writer and director of Matewan, produces for the audience a true depiction of the West Virginian coal-mining community of 1920. At a surface-level viewing and examination of the film, many might be tempted to view the environment that is created as capitalist. After all, the workers do get paid for their services. However, upon a much deeper, more in-depth inspection one could argue that there is much evidence toShow MoreRelatedThe Fall Of Feudalism And The Rise Of Capitalism1304 Words   |  6 PagesThe fall of feudalism in the 12th century eventually led to the rise of capitalism. To get there, the first thing needed was a change in thinking. This began with the scientific revolution, and led to the Enlightenment in the 18th century. The Enlightenment, also known as the Age of Reason, was highlighted by individualism, reason, and skepticism. Skepticism caused people to denounce divine right of kings, thus moving from monarchies to democracies. This desire fo r knowledge coupled with the scientificRead MoreKey Differences Between Feudalism And Capitalism996 Words   |  4 Pagesdifferences between feudalism and capitalism. Explain how Heilbroner discusses the rise and establishment of capitalism? In this short essay, I will explain few key differences between feudalism and capitalism based on Heilbroners book. They are as follows: the property rights (Land), the system of wage and labor (Workers), and the existence of competition. Additionally, I will discuss the rise of capitalism based on Heilbroner point of view. Both feudalism and capitalism are defined by manyRead MoreTo What Extent Is American Capitalism Representative Of European Medieval Feudalism?2015 Words   |  9 PagesExtent is American Capitalism Representative of European Medieval Feudalism? American capitalism is the foundation by which economic growth has propelled the U.S. economy to be a powerhouse. 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Capitalism in essence, is a system of economic value in which private ownership is the source of production (Such as factories, and farming). Goods are produced and in return, income and profit are gained. The generally accepted characteristics of what Capitalism is, such as private property rights, specialization of jobs, profits, division of labour, did not originate around Capitalism. In actuality, these were just the stepping stonesRead MoreThe Communist Manifesto By Marx943 Words   |  4 Pagespeople’s ancestors were lazy and capitalism starts with violence of one class against another. Marx mentioned, â€Å"The history of all existing societies is the history of hitherto class struggles†, struggles between oppressors and oppressed. In history, Ancient slavery and society evaluated over time to feudalism than to capitalism where minority and majority groups existed. The minority group in ancient slavery and society was the kings and the majority was the slaves. Feudalism, the minority was the lordsRead MoreKarl Marx And The Productive Power1182 Words   |  5 Pagessocial rebellion. In the following chapters I will explain how the mode of production for feudalists, capitalism, and socialism will possibly lead to communism. I will elaborate on the social conflict, exploitation faced by the oppressed, and why Marx believed that the mode of production from these classes, except communism will inevitably self-destruct. Feudalism The very definition of the term feudalism as it relates to the 19th century is that of a dominant social system in medieval Europe, in whichRead MoreMain Reasons for the Fall of Feudalism1067 Words   |  5 PagesFeudalism developed as a result of the frequent invasions made by the vikings during the Middle Ages around the 900s to early 1500s. Feudalism served its purpose by creating a system where the king would appoint lords that would appoint knights to appoint serfs that would be expected to work the land and fields in exchange for food, protection, and accommodations. It provided stability because lords were able to govern smaller groups of people through a system called manorialism. Feudalism allowedRead MoreWays in Which the French Revolution had a Lasting Impact on France853 Words   |  4 PagesFrench Revolution. This in itself shows that the revolution had a major impact on France. It played a significant role in changing France through, for example, the new definition of nationalism, the abolition of the monarchy and the abolition of feudalism. Whether these changes succeeded in modernising France or resulted in something that was not any better than pre-revolutionary times is what will be discussed in more detail using the above three examples. Nationalism did exist, to a certain extentRead More The Formation of Capitalism in European History Essay1354 Words   |  6 PagesThe Formation of Capitalism in European History Pure capitalism is characterized by private ownership of resources and by reliance on markets, in which buyers and sellers come together and determine what quantities of goods and resources are sold and at what price. Here no central authority oversees production and consumption. Rather, economic decisions are coordinated by the actions of large numbers of consumers and producers, each operating in his or her own self-interest. Because property

Opportunities Their Respective Potentials †Myassignmenthelp.Com

Question: Discuss About The Opportunities Their Respective Potentials? Answer: Introducation The case organization Nokia, is Finnish multinational in information technology and communication business. The company has several divisions/avenues through which it operates and transacts business. Among these divisions is the handset division which has a reputation across the world for its durable and reliable handsets with wide market acceptance across the world. (Pai, 2015). Project topic In the year 2014 Nokia Corporation sold its handset making division to Microsoft Corporation and decided to focus on its other areas of its telecommunication business. However three years later in 2017 Nokia is making a comeback into mobile phones market by introduction of a trio three of Nokia branded phones running on Android operating s namely Nokia 6, 5 and 3. One of the biggest opportunities Nokia Corporation can leverage on as it attempts to gain a market share in Smartphone business is their brand name. Many consumers still recognize Nokia phones because of their reliability and durability. Perception is everything in sales once a product has a good perception in the market even if it disappear for a while consumes will likely receive it back well if its re-introduced. The phones also tend to have much higher resale value compared to other brands which exist in the market. They are also easy to use and the lower segment of the Smartphone market will likely prefer Nokia brands over competition. The price range is also wide which in turn translates to wider market for the Nokia brand of handsets. (Leelakulthanit and Hongcharu, 2012) Purpose of the research Therefore, the purpose of this research is to carry out an investigation into opportunities available to Nokia for its handset division even as it embarks on reintroducing the devices back into the market. The research will analyze and highlight these opportunities to Nokia Corporation and make recommendation on how best it can tab on them in order to successfully re-launch its handset product back into the marketing. (Allen, Graupera and Lundrigan, 2010) The following concepts/theories relate to this topic. PESTLE analysis SWOT analysis The research will take the form of single case study in the name of Nokia corporation handset division as a unit of analysis. The secondary data will be collected from a number of previously done researches on the same topic as well as other forms of publications that fall within the area of study of this particular research. In particular the research will leverage on the following industry reports Global Market Analysis and Outlook: Disruption In Change Market (Anon, 2017) and Smartphones Market Trends (Strategyr.com, 2017) among other industry related reports. The research will also draw secondary data from Nokias annual reports (Nokia, 2011; Nokia 2012; Nokia 2014). The information will be used to indentify opportunities available in Smartphone sectors and draw comparisons to Nokias opportunities. The research will utilize both qualitative and quantitative data analysis to identify Smartphone market opportunities available in the market and quantify these opportunities to see the ir respective potentials. References Allen, S., Graupera, V. and Lundrigan, L. (2010). Pro Smartphone Cross-Platform Development. Berkeley, CA: Apress. Anon, (2017). Global Smartphone Market Analysis and Outlook: Disruption in a Changing Market. [online] Available at: https://www.lenovo.com/transactions/pdf/CCS-Insight-Smartphone-Market-Analysis-Full-Report-07-2014.pdf [Accessed 14 Sep. 2017]. Behrer, M. (2011). How Cool Brands Stay Hot. Kogan Page. DePamphilis, D. (2016). Mergers, acquisitions, and other restructuring activities. Amsterdam: Elsevier Academic Press. Ford, C. (2013). Smartphone Apps on the Mobile Web: An Exploratory Case Study of Business Models. SSRN Electronic Journal. Lee, G. (2016). Analysis of Characteristics of Smartphone M-Commerce Users. The e-Business Studies, 17(1), p.173. Leelakulthanit, O. and Hongcharu, B. (2012). Factors Influencing Smartphone Repurchase. Journal of Business Economics Research (JBER), 10(11), p.623. Mallegg, K. (2014).Business plans handbook. Nicholson, A., Elad, J. and Stolarz, D. (2010). Starting an iPhone application business for dummies. Hoboken, N.J.: Wiley. Pai, V. (2015). Nokia Ltd: Travails of a Market Leader. Vision: The Journal of Business Perspective, 19(3), pp.276-285. Strategyr.com. (2017). Smartphones Market Trends. [online] Available at: https://www.strategyr.com/MarketResearch/Smartphones_Smart_Mobile_Phones_Market_Trends.asp [Accessed 14 Sep. 2017]. Tavana, M. (2012). Developing business strategies and identifying risk factors in modern organizations. Zammetti, F. (2013). Pro iOS and Android Apps for Business. Berkeley, CA: Apress.

Notes Chris Cunningham Case Essay Example

Notes: Chris Cunningham Case Essay He has good qualities. This could be done by refusing him new clients, giving him a performance review, making public high level disapproval of his tactics. Tie production to consumption. Make it clear to Chris that his income will be affected if he continues. Following this point, Opponent urged consideration of why Chris finds it so easy to influence production. He has close personal ties to Mrs.. Stoves. Staff are probably gossiping about favoritism, adding to resentment. 2. Mention a possible career path to sales director, and the need to change his behavior if he wants such promotion. Some students perceived this as apparently rewarding undesirable behavior. Opponent pointed out that, as Chris works on commission, his behavior is already rewarding him. 3. In tackling this herself Mrs.. Stoves is undermining the sales director. Theres a problem with the organizational structure. 360 degree feedback should be employed to get other peoples perceptions of Chrisms behavior. We want Chris to honor lines of authority. 4. Focus on head of production. Give him more prestige, perhaps Chris should report to him. 5. Problem with production maybe not enough, so build up inventory, and reduction capacity, outsource. 6. Problem with sales director, only a figure head. Give him the power to solve problem. 7. Fire Chris. Opponent made the point that all of these actions would destroy Chrisms productivity! However, Chrisms sales are not the same thing as the company profitability, even if he thinks they are the same. What is his behavior costing the company? Not only in money, but in human relationships. Citing a toy company he had advised in LA, Opponent said that this question may not be one that the accounting department could answer. We will write a custom essay sample on Notes: Chris Cunningham Case specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Notes: Chris Cunningham Case specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Notes: Chris Cunningham Case specifically for you FOR ONLY $16.38 $13.9/page Hire Writer He also mentioned the Japanese solution to this problem, which would be to job-rotate Chris to work in production. However, all his experience is in sales, due to the divided structure of the company. Another set of actions was proposed by the students: 1 . Bring in just-in-time so that production will be flexible enough to meet Chrisms needs. Change organization to support Chris-type salespeople. 2. Rank customers by profit they bring and prioritize production accordingly. Therefore, 2 main options: Restrain Chris, and change organization to do dhal r use him as he is and change organization to support him.

Calcium Carbonate and Ca2+ Ions Essays

Calcium Carbonate and Ca2+ Ions Essays Calcium Carbonate and Ca2+ Ions Paper Calcium Carbonate and Ca2+ Ions Paper Experiment. EDTA Titration of Ca2+ in an unknown solution Experiment. EDTA Titration of Ca2+ in an unknown water sample Modified 9/2012 Objective: The most common multivalent metal ions in natural waters are Ca2+ and Mg2+. In this experiment, you will find the total concentration of calcium ions that can react with EDTA with the assumptions that EDTA reacts 1:1 with metal (Ca2+) ions. Equipment 250-mL Erlenmeyer flask (3) 50-mL Buret Ring-stand and hardware Desiccator 400-mL Beaker 500-mL Vol. flask 250-mL Vol. flask 1. 0-mL Vol Pipette 100-mL Grad cylinder Hot plate Safety and Waste Disposal Chemicals Buffer (pH 10): Add 142 mL of 28 wt % aqueous NH3 to 17. 5 g of NH4Cl and dilute to 250 mL with water. Eriochrome black T indicator: Dissolve 0. 2 g of the solid indicator in 15 mL of triethanolamine plus 5 mL of absolute ethanol. 50 wt % NaOH: Dissolve 100 g of NaOH in 100 g of H2O in a 250-mL plastic bottle. Store tightly capped. When you remove solution with a pipet, try not to disturb the solid Na2CO3 precipitate. Discussion: Hard water is due to metal ions (minerals) that are dissolved in the ground water. These minerals include Ca2+, Mg2+, Fe3+, SO42-, and HCO3-. Generally hard water arises because rainwater moves through limestone, CaCO3 underground that occurs in our area to the aquifer. This is why we measure hardness in terms of CaCO3. The concentration of the Ca2+ ions is greater than the concentration of any other metal ion in our water. The determination of water hardness is routinely used to measure the quality of water that the general public uses. Originally, water hardness was defined as the measure of the capacity of the water to precipitate soap. Hard water is not a health hazard since the main chemical in hard water is calcium. People regularly take calcium supplements. In fact, hard water can be a source of necessary minerals (calcium and magnesium) that is necessary for good health. Indeed, the National Academy of Science go so far as stating that that consuming extremely hard water could be a major contributor of calcium and magnesium to the diet. The problem with hard water is that it cause soap scum, clog pipes and clog boilers. Soap scum is formed when the calcium ion binds with the soap. This causes an insoluble compound that precipitates to form the scum you see. Soap actually softens hard water by removing the Ca2+ ions from the water. When hard water is heated, CaCO3 precipitates out, which then clogs pipes and industrial boilers. This leads to malfunction or damage and is expensive to remove. There are two types of water hardness, temporary and permanent. Temporary hardness is due to the bicarbonate ion, HCO3-, being present in the water. This type of hardness can be removed by boiling the water to expel the CO2, as indicated by the following equation: HCO3- (aq) ? H2O (l) + CO2 (g). Because bicarbonate can be removed it is classified as temporary hardness. Permanent hardness is due to the presence of the ions Ca2+, Mg+2, Fe3+ and SO4-2. Because boiling cannot eliminate this type of hardness, the water is said to be permanently hard. The table below shows the degree of hardness of the water in terms of its calcium carbonate concentration in ppm and grains. Hardness rating Soft Medium Hard Hard Very Hard Concentration of Calcium Carbonate (mg/L or ppm) 0 75 75 to 150 150 to 300 300 and greater Concentration of Calcium Carbonate (grains/US gallon) 0 to 5. 2 5. 2 to 10. 5 10. 5 to 21 21 and greater Permanent hardness is usually determined by titrating it with a standard solution of ethylenediamminetetraacetic acid, EDTA. The EDTA is a complexing, or chelating agent used to capture the metal ions. This causes water to soften, but the metal ions however, are not removed from the water. EDTA simply binds the metal ions so that the ions do not precipitate to form soap scum. EDTA is a versatile chelating agent. A chelating agent is a substance whose molecules can form several bonds to a single metal ion. Chelating agents are multidentate ligands. A ligand is a substance that binds with a metal ion to form a complex ion. Multi-dentate ligands are many clawed, holding onto the metal ion to form a very stable complex. EDTA can form four or six bonds with a metal ion. It is frequently used in soaps and detergents because it forms complexes with calcium and magnesium ions. The ions in hard water are bound to the EDTA and cannot interfere with the cleaning action of the soap or detergent. EDTA is also used in foods. Certain enzymes are responsible for food spoilage. EDTA is used to remove metal ions from these enzymes. It is used to promote color retention in dried bananas, beans, chick peas, canned clams, pecan pie filling, frozen potatoes and canned shrimp. It is used to improve flavor retention in canned carbonated beverages, beer, salad dressings, mayonnaise, margarine, and sauces. It inhibits rancidity in salad dressings, mayonnaise, sauces and salad spreads. In this lab you will be asked to determine the total permanent hardness. EDTA grabs all the metal ions in the water, not just the Ca2+ ions. This gives us a value that is not truly the concentration of Ca2+ ions. This causes an experimental error of about 1%, which is acceptable due to the fuzzy endpoints in this type of titration. Erio-T indicator or Eriochrome Black-T indicator is used in this titration. When it is chelated or acidifies, it produces a Pink-Red solution. When it is not chelated and under basic conditions it is Blue. The three pictures show the end point in this titration. There is a 1-drop difference of 0. 01 M EDTA between the first and second pictures and between the second and third pictures. Two or three seconds were allowed for colors in the second and third pictures to develop after adding the additional drop. In each case the solution was thoroughly mixed. This color change from wine red to violet to blue is due to the compact nature of the complex. Experiment. EDTA Titration of Ca2+ in an unknown solution PROCEDURE Modified 9/2012 1. Dry Na2H2EDTA. 2H2O (FM 372. 24) at 80 ° C for 1 h and cool in the desiccator. Accurately weigh out ~ 0. 6 g and dissolve it with heating in 400 mL of water in a beaker. Cool to room temperature pour into a 500-mL volumetric flask. , mix and dilute to the mark. 2. You should practice finding the end point several times by adding a little tap water in a clean beaker and titrating with EDTA. Save a solution at the end point to use as a color comparison for other titrations. 3. Pipet a 1-mL sample of unknown into a 250-mL flask and fill to the mark with deionized water. Mix thoroughly. From this 250-mL stock solution draw 4, 50mL aliquot samples and place each aliquot in 250mL Erlenmeyer flasks. To each sample, add 3 mL of pH 10 buffer and 6 drops of Eriochrome black T indicator. To the first 50-ml solution, titrate with EDTA from a 50-mL buret and note when the color changes from wine red to blue. 4. Repeat the titration with the next three samples to find an accurate value of the total Ca2+ concentration. Perform a blank titration with 50 mL of distilled water and subtract the value of the blank from each result. 5. Upon completion of the experiment, discard all solution in a chemical waste bottle and wash out the glassware. Be sure to dry your buret in the upside down position. _________________________________________________________ Calculations – Analysis: Analyte Ca2+ The reaction of Ca2+ ions with H2EDTA2- takes place with a 1:1 stoichiometric ratio: Ca2+ + EDTA2- ? At the end point of the titration, 1-equivalent of Ca2+ reacts with one equivalent of H2EDTA2-. 1 eqv Ca2+ = 1 eqv H2EDTA2-; equivalent Ca2+ = [H2EDTA2-] Vol EDTA CaH2EDTA. Recall that the analyte (we call this unknown solution) was prepared by taking exactly 1-mL of the unknown solution and diluting in a 250-mL volumetric flask (we will call this the stock solution) 50-mL aliquot (call this the analyte) of this solution was then titrated against EDTA. Note that the analyte concentration is equal to the stock solution concentration. The mass Ca2+ in 1 mL aliquot unknown: Mass of Ca2+ in 50mL Sample = H 2EDTA2? $ Vol EDTA $ = mol H 2EDTA2- = mol Ca2+in 50mL Analyte # % # % Mass of Ca2+ in 1mL of unknown = mol Ca2+ ? 250mL aliquot Ca2+ __ g Ca2+ ? 50mL Analyte mol ? ? Dilution Factor Atomic mass Ca Mass of Ca2+ in 1 L solution: Mass Ca2+ in 1 L = mass Ca2+ in 1 mL Aliquot 1000 mL 1 mL Concentration of unknown by percent (m:v), parts per hundred (m:v) and Molarity (M): Mass Ca in 1mL aliquot Vol aliquot solution used % Ca2+ m:v = 100 ppm Ca2+ m:v = Mass Ca in 1mL aliquot Vol aliquot solution used 106 Molarity Ca2+ = mass Ca2+ in 1mL 1 mol Ca __g Ca ? ? ? molar mass Ca 1 Volume in L of unknown Aliquot used Mass in grams of calcium carbonate unknown in 1L solution: Mass CaCO 3 in 1-L = mass ppt (g) 1 mol CaC 2O 4 H 2O __ g CaC 2O 4 H 2O ? molar mass CaC O H O 2 4 2 1 mol CaCO 3 1 mol CaC 2O 4 H 2O 1 mol CaCO 3 Vol in L of aliquot ? ? ? ? Molar mass CaCO 3 __ g CaCO 3 1L Dilution Factor Statistical Analysis – 1. Report the mean, medium, standard deviations (s), relative standard deviation (RSD), variance (s2) and the 95% confidence interval for your results. 2. 3. 4. Apply the student’s t test at the 95% confidence interval Apply a Q-test to any suspected result. Confidence interval = x + ts n 5. Compare the results of this experiment to the previous experiment, Gravimetric determination of Ca. Apply the Comparison of Means with Student’s t, Case2 (p76) Comparing Replicate Measurements. Do the two methods agree within the 95% confidence interval? â‚ ¬ Test for Outlier Apply a Grubb’s Test and Q-Test for any suspected outliers at 95 % level. See page 83 of text for critical values for 95% confidence. If your results show an anomalous data then use the Q-test to determine if the result should be rejected. Q= (Suspected Value Nearest Value) (Suspected Value Furthest Value) G calc = | Questionable value x| s Table of Data, Results and Statistical Analysis: Calcium Raw Data 1. Unknown number 2 Mass of EDTA used 3 Concentration of EDTA 4 Volume of Unknown Ca2+ Solution 5 Volume EDTA during titration 6 Volume EDTA for blank trials 7 Q-Test (95%) of any outlier Analysis and Results 8 Mass of calcium in 1-mL aliquot (Average) 9 Mass of calcium in 1-L solution (Average) 10 Conc. of calcium, %, ppm (m:v) and Molarity (Average) 11 Mass of calcium carbonate in 1-L (Average) Statistical Analysis 12 Averages and Standard deviations of all results 13 Variance, RSD and CV of all results 14 95% Confidence interval 15 ttable and tcalc for replicate measurements DiscussionThe goal of this experiment was to determine the â€Å"hardness† of the unknown sample by calculating the concentration of calcium ions in an analyte solution. Correcting for dilution factors, the concentration of calcium in the unknown in g/L is to be determined and compared to analysis for calcium by EDTA titration. Statistical analysis is applied to the results. A discussion of this experiment should include the accuracy and precision of this experiment compared to the EDTA titration method. An analysis of a comparison of replicated measurement is performed and discussed. Table of results should include Include in your summary table the following: i) Moles of Ca2+ in the unknown and the average equivalent value. ii) Concentration of [Ca2+ ] in the unknown in molarity, ppm and g/L iv) Mean, standard deviations, RSD and CV for each of the above concentration units. v) Student’s t at the 95% confidence interval vi) Application of a G and Q-test to any suspected result at the 95% level. vii) ttable, tcalc, Conclusion on comparison of replicated measurements. . Experiment. EDTA Titration of Ca2+ in an unknown solution Modified 9/2012 Sample data table. Sample Unknown # ______ Mass Na2EDTA, (g) Molarity Na2EDTA, (M) Vol. unknown, (ml) Buret Volinitial, (ml) Buret Volfinal, (ml) Volume EDTA used, (ml) Vol EDTA for blank, (ml) Corrected Col EDTA, (ml) Trial 1 Mass Ca2+ in 1 ml aliquot (g) Mass Ca2+ in 1-L solution (g) Concentration Ca (%) Concentration Ca (ppm) Molarity Ca2+, unknown (M) Mass calcium carbonate in 1L Q and G Test for Outliner CaCO3 (g/L), unknown Trial 2 Trial 3 Trial 4 Average Std dev Variance RSD , CV 95% CL Trial 1 Trial 2 Trial 3 Trial 4 Blank Student’s t Analysis: Comparing replicate measurements Analysis A: CaCO3 (g/L) 1 2 3 4 Trial 1 Trial 2 Trial 3 Trial 4 Avg Avg X1bar X2bar Sqrt ((n1*n2)/(n1+n2)) (xi-x1)^2 deg freedom Spooled Expt 2 Expt 3 Ex2 (Xi-Xbar)^2 Ex3 (Xi-Xbar)^2 T calc t table Conclusion T calc ? T table, at 95%, two result are (not) considered to be different EDTA Titration of Ca2+ in an unknown solution. # 1 2 CRITERIA (Tentative point distribution may change depending on experiment) Quiz / Homework [NONE} Introduction and Procedures A. Introduction Objective of Expt. Background information. Math relationship used in study. B. Procedures Outline of procedures in Expt. Flow chart pictorial of procedures. Procedural changes. Information (data) to be recorded during experiment. (to be presented in Table form. ) Safety and disposal information. This portion of the report should be turned in before the start of lab class (prelab discussion). Data, Observe. , Results and Calc. C. Data and Observation Data in table form. detailed observations written in th e table. All data entry should contain the proper number of significant figures and units. Data should always be recorded in an organize fashion. Balance chemical equations; all chemical reaction which occurred during an experiment should be written in this section. Then it should also be written in the discussion portion of the report. This portion of the report should be turned in before you leave the laboratory. Calculations Results D. Calculations Sample calculation shown with Excel spreadsheet available with formulas shown Statistical analysis of data and result. Avg, Std dev, RSD, CV E. Results Summary of Result(s) in table form. In this section accuracy of results is very important as well as detailed calculation showing how the result was obtain. Unknown will also be included in this section. Discussion / Conclusions and Post-Lab Questions F. Discussion (Talking points) What is your final result in this experiment. Are the four trials consistent with each other? If not what would account for the inconsistencies? How did the results in this experimental result compare to the result in experiment 2? Is your result for the amount of calcium carbonate in your unknown within the range of 10 – 25 g/L? Elaborate on this. What is the average amount of calcium in tap water, how much more higher is this unknown compared to the average content in tap water (express in %). G. Conclusion Summary of the goal of the experiment and how that goal was achieved in the experiment. H. Post-lab questions or Editorial comment What did you learn in this experiment? What skills in lab practice did you develop through this expt? This portion (Calculation and Discussion) is turned in at the beginning of class of the due-date Overall Presentation (of lab notebook) Lab technique during experiment; example are, class preparation, safety glasses precautions and leaving the laboratory clean. Report presentation: examples are the headings of each report that includes name, title, lab partner, date and section #, witness signature. Legibility of report. Is the report easy to read or is important information jotted down by small print in the corners of the lab report. The overall impression is important. Lab Technique Safety: wear goggles, handle chemicals with caution, proper handling of lab equipment Leave lab clean and tidy Score ______/10 _______ Student’s t ____/5 pts % Score 5 3 5 5 5 4 5 5 5 6 5 Unknown __________% Error Total (This total may be adjusted d epending on lab technique and student conduct in the experiment) 50