To determine enthalpy change Essay Example for Free

To determine enthalpy change Essay Chemistry Lab report 1) Experiment No: 8A 2) Objective: To determine the heat of formation of calcium carbonate. 3) Date: 26th Nov, 2010 4) Theory: The experiment consists of 2 parts: a) In the 1st part, an accurately weighed known mass of calcium is added to a given dilute hydrochloric acid. During the addition, the following occurs: Ca(s) + 2H+(aq) Ca2+(aq) + H2(g) With the help of the data of heat change of the solution mixture, the average heat evolved by one mole of calcium during the reaction can be calculated. b) In the 2nd part, an accurately weighed known mass of calcium carbonate is added to a given dilute hydrochloric acid. During the addition, the following occurs: CaCO3(s) + 2H+(aq) Ca2+(aq) + CO2(g) + H2O(l) With the help of the data of heat change of the solution mixture, the average heat evolved by one mole of calcium carbonate during the reaction can be calculated. After that, by using a suitable energy-cycle diagram, and applying Hesss law, the heat formation of formation of calcium carbonate can be calculated. 5) Procedure: Please refer to the lab. manual 6) Data: 1st Part: Reaction of calcium with dil. Hydrochloric acid Experiment No: 1 2 Mass of Ca used / g 0. 53 0. 51 Volume of hydrochloric acid used: 100cm3 2nd Part: Reaction of calcium carbonate with dil. Hydrochloric acid Experiment No: 1 2 Mass of CaCO3 used / g 2. 13 2. 05 Molar mass of calcium carbonate = 100 g/mol Volume of hydrochloric acid used = 100 cm3 7) Calculation: Note: No temperature drop can be observed after the max temperature is attained for 4 readings. Note: No temperature drop can be observed after the max temperature is attained for 4 readings. Extrapolation procedure cannot be done. Therefore, the temperature change of 1st part exp. = 28-25 = +3oC the temperature change of 2nd part exp = Enthalpy change in 2nd parts reaction Hf [H2O(l)] = -242000 J mol-1 Hf [CO2(g)]= -393500 J mol-1 source: physical chemisty I of Fillans By Hesss law: Hf[CaCO3(s)] = H1 + Hf [H2O(l)] + Hf [CO2(g)] H2 = -688. 79 kJ mol-1 8) Discussion 1. Why is the exact concentration of hydrochloric acid unimportant? The exact concentration of the hydrochloric acid was unimportant as it was present in excess, that was, to provide enough H+(aq) to react with calcium. At the same time, the exact concentration of hydrochloric acid would affect the calculation afterwards. 2. State the law which you use for calculating the heat of formation of calcium carbonate. On which thermodynamic principle does it depends? The law used was the Hesss law. It depends on the standard enthalpy change of a reaction is independent of the route by which the chemical reaction takes place, which only depends on the difference between the standard enthalpies of reactants and products, i. e. conservation of energy. 3. Why is this law useful? This principle is useful as the standard enthalpy change of some reaction might not be able to find directly, and thus Hesss law can be used and the standard the enthalpy change of the reaction can be calculated indirectly by this method. 4. Discuss the possible sources of errors. State how to minimize the possible errors. A. The solid labeled calcium is suspected to be calcium oxide, which show white color but not grey shinny color. B. Heat produced the reaction might heat up the air inside the beaker, which cannot be avoided. C. Error in reading thermometer D. Error in weighing.

Comparing Felicite of Flauberts A Simple Heart and Nelly Dean of Brontes Wuthering Heights :: comparison compare contrast essays

Comparing Felicite of Flaubert's A Simple Heart and Nelly Dean of Bronte's Wuthering Heights Nelly Dean and Felicite are both characters that are in stark contrast to the characters that surround them. They are both good Christian women in there own way who are serving those who have no real interest in godliness and place no real emphasis on it. Nelly Dean is a realistic character in a romantic novel, while Felicite is a romanticized character in a realistic story. Nelly Dean is a servant in a household that is filled with people that are difficult to get along with. They are in constant turmoil with each other, and they almost seem to enjoy the conflict they cause. Nelly Dean is the one character that does not usually allow herself to be pulled into the conflicts that the rest of the characters embroil themselves in. She is able to stand back from the situation and give sound advice. Felicite does not seem as able to distance herself from the problems around her until she gets older and is physically unable to participate. Both women are passed from master to master because of no true faults of their own, and neither woman seems to have much control over her own destiny. While Nelly Dean stays with the same family, she has to move and get accustomed to new bosses every time some one dies. Felicite just seems to have plain bad luck in her choice of employers at the beginning of her career. In spite of this, both women seem quite satisfied with their lives, while the people who are in charge of them seem a lot less happy with their own lives. The characters in ‚"Wuthering Heights‚" frequently have severe fits of negative emotion, while Nelly quietly looks on. The only time that we see Felicite completely overcome with grief is when she thought she was going to have control, and she lost it. This happens when Felicite is still relatively young. She falls in love with a boy, and when he decides to marry some one else, ‚ÄÃ ºshe threw herself on the ground, screamed, called to the God of mercy, and moaned‚ÄÃ ¹ (1021). After this first display of emotion, she picked herself up and moved on with her life.

Embarrasing Moment

My most embarrassing moment I consider myself to be one who doesn't easily get embarrassed, but one of my most embarrassing moments happened this past summer. It all started when a few friends of mine decided that since it was incredibly hot out that summer day, that we should all go down to Tubbs hill for a swim. I’m not sure if you realize how busy downtown is during mid-summer season, but understand it’s almost always completely jammed full of people trying to fight off the blistering sun.So my friends and I hiked up the path to get a good spot to start jumping off the rocks and start swimming, but all the great spots were all full. We decided to just find a close spot and just deal with all the people in the area. Our day progressed as normally as you’d expect, and everyone was enjoying the water and how refreshing it was fighting off the heat of the day. Eventually everyone was starting to get bored jumping off the smaller rocks as well as just swimming arou nd, so my friends decided we should start jumping off the higher rocks. Eventually it came to my turn to jump and I went for it.As I dived into the water I didn’t realize at the time the sheer pressure on my swim shorts, but once I broke the surface of the water for air it struck me. I had lost my swim shorts on the dive, so I was sitting in the water completely nude in front of all my friends and random strangers that were watching. I franticly searched for my swim shorts, but to no avail, they were lost. Eventually a friend brought me a towel so I could get out of the water and return home. I would have to say that this was one of the most extremely embarrassing moments I’ve had so far in my lifetime.

The Tragic Outcome Of The Monstrous Isolation Frankenstein...

Now the final facet to discuss is the tragic outcome of the monstrous isolation Frankenstein and the Monster suffer--their demise. It is a twofold blow of a personal inability to escape isolation’s grasp coupled with zero chance of outside help because of the isolation that sends both inexorably to expiry. The Monster simply wants to, â€Å"become an actor in the busy scene where so many admirable qualities were called forth and displayed,† (130) due to the lesson he learns from the cottagers but from which he is totally excluded. So a solitary solution to his troubles is not possible to begin with. Unfortunately, in his life long search for inclusion, he is turned away from first his creator then the rest of his chance encounters with humanity due only to his monstrous form that no one could imagine could contain any human capacity for friendship, which his unnatural birth imbued him with. Even his plea for a second like him is eventually rebuked by Frankenstein, the o ne man most likely and farthest from helping him. His isolation truly sealed, the Monster is left with no purpose but to dedicate his life to torturing humanity and his creator, which leads Frankenstein to kill himself, leaving him nothing but the solace of death. For Frankenstein, it is not so simple. To begin, it is his guilt, as if for a crime, for being the man to â€Å"[turn] loose into the world a depraved wretch, whose delight was in carnage and misery,† (78) that haunts his every waking thought. Frankenstein’sShow MoreRelatedThe God Facade : A Look Into Mary Shelley s Frankenstein And The Dangers Of Playing God1209 Words   |  5 PagesThe God Faà §ade: A Look into Mary Shelley’s Frankenstein and The Dangers of Playing God. Frankenstein by author Mary Shelley is a Gothic science fiction novel written in Switzerland between 1816–1817, and published January 1, 1818. Set in eighteenth century Geneva, Frankenstein tells the story of a young man named Victor who goes away to college to study natural philosophy, chemistry, and alchemy. When armed with the knowledge he has long been seeking, Victor spends months constructing a creature

Drinking Water Is Safe For Bottled Water - 1272 Words

Everyone wants to know which water is safe for them, is it bottled water or tap water? The US drinks more bottled water than any other country across the globe. Not only does the US consume more bottled water, but uses a lot of energy to produce the bottled water. In developing countries, tap water is safe and ‘drinkable’. Bottled water and tap water come from the same sources, but tap water is better than bottled water. Some ways in which tap water is better than bottled water is the cost, environmental impact, and safety. Researchers have shown that majority of people spend so much money buying bottled water daily and yet they have tap water that’s almost free. The amount of bottled water consumed per day around the global is more than that of tap water. An article from the USA Today Magazine states, â€Å"... demand for bottled water is increasing--producing unnecessary garbage and consuming vast quantities of energy. In the industrial world, bottled water is considered to be healthier than tap water because bottled water costs more than tap water. Bottled water can cost up to 10,000 times more. At as much as $2.50 per liter, bottled water costs more than gasoline.† According to the article, the demand for bottled water is increasing and that’s causing environmental concerns and using a large amount of energy. The industries that manufacture and produce bottled water need a lot of energy to purify the water and make the bottles. It is expensive for retailers to buy bottledShow MoreRelatedBottled Water And Water Treatment Process Levels Essay1242 Words   |  5 PagesFirst, water is an important resource for consumers and the environment. Water is needed in the body to maintain health and the body’s mechanism. â€Å"People cannot survive without water resources in their everyday lives, which cost, taste, or health factors the cause for choice and how water consumption affects people and the environment† (Mythri , Chandu, Prashant, Subba, 2010, p. 515). The challenge is understanding the risk of drinking water, from either bottled water or tap water, and the adverseRead MoreThe Choice Of Bottled Water Over Tap Water Essay1247 Words   |  5 PagesChoice of Bottled Water over Tap Water First, water is an important resource for consumers and the environment. The body needs water to maintain health and the body’s mechanism to work properly. â€Å"People cannot survive without water resources in their everyday lives, which cost, taste, or health factors the cause for choice and how water consumption affects people and the environment† (Mythri, Chandu, Prashant, Subba, 2010, p. 515). The challenge is understanding the risk of drinking water, from eitherRead MoreEssay about Water Purification for Safe Drinking Water580 Words   |  3 PagesWater Purification Safe drinking water is essential to every living being. Access to safe drinking water has improved over the past years, but still approximately one billion people are deprived of safe and clean water. Over 2.5 billion people have no access to adequate sanitation. A report, issued in November 2009, suggests that by 2030, in some developing regions of the world, water demand will exceed supply by 50% and approximately 70% of the fresh water used by humans goes to agriculture. PeopleRead MoreThe Effects Of Bottled Water On Human Being s Health And The Natural Environment1677 Words   |  7 PagesBottled water is one of products popularly consumed back to a few decades. Result from the production of bottled water, people likely prefer to drink bottled water than tap water while some researches find out the fact that water in bottle are not as safe as water provided by state companies. Why people choose to drink bottled water and whether bottled water is pure as advertisement are the crucial concerns, together with the effect of bottled water on human being’s health and the natural environmentRead MoreDrinking Bottled Water Is Not Good For The Environment1006 Words   |  5 Pageson buying bottled water. What they don t know is the difference between bottled and tap water. People buy bottled water because they think it s safer to drink. What they don’t know is that bottled water is bad for the environment. Bottled water manufacturers begin by putting the water into plastic bottles which then is shipped from one part of the world to another and then kept refrigerated before they sell it. Not only that, but people around the world are lacking safe drinkable water and are dyingRead MoreTap Water Vs Bottled Water957 Words   |  4 PagesTap water vs bottled water. One of the most significant resources in our life is water. However, when it comes to drinking water, people should be careful on choosing whether the water they are drinking is pure and healthy for them or not. People can make their own choice to drink a tap water or bottled water. Most people believe that bottled water is healthier than drinking tap water. However, they should take a look at the adverse effects of bottled water before they consume it. BottleRead MoreBenefits Of Drinking Bottled Water Essay1171 Words   |  5 PagesThere are many benefits of drinking bottled water, but these benefits do not outweigh the costs. Drinking bottled water can have many negative effects on human health, and can be very harmful to the environment. Over the past ten years, the bottled water market has tripled. Every year the market grows ten percent from the previous year. Because the market is continuously growing, the amount of negative impacts of bottled water are also growing. Bottled water has been linked to health defects, illnessesRead MoreWater Contamination, Tap Water Vs Expensive Bottled Water1633 Words   |  7 Pagesby this experiment that we recently did on water contamination, tap water versus expensive bottled water. Our water is tap well water. While exploring the topic futher, our research area took place on our kitchen counter where we observed how the test chemicals reacted with the tap water versus the bottled waters. We needed to follow the directions thoroughly, so we got accurate results. We started with test strips of ammonia: all three glasses of water contained: 0 mg/L of ammonia, 0 mg/L of chlorideRead MoreWater Quality And Contamination. Introduction. Background:.1405 Words   |  6 PagesWater Quality and Contamination Introduction Background: Drinking water is vital to the health and well-being of human life, without it, life does not exist. Human bodies are composed of 60 percent water. Drinking healthy water is important to maintain a healthy balance of body fluids. Tap water and bottled water in general are safe to drink, the question is how safe and what are you willing to pay to consume healthy, safe water. Most Americans assume the Environmental Protection Agency is protectingRead MoreBottled Water And Its Effect On Our Society877 Words   |  4 Pagescitizens with safe and reliable means of drinking water. This was a tragic incident for the environment as well as the world’s citizens. While thousands of North Americans desire for bottle water increased, this gave corporations the opportunity to swoop in and save the day, and of course make a profit. This dawned the era of bottled water. Corporations began selling pre bottled â€Å"safe† water for the public to drink. People then began to get hooked o n the convenience of bottled water, and lost faith

The Democratic Alliance and the Future of South Africa

Good morning. As a representative and leader in the Democratic Alliance, I have come here today to explain to you why the DA sees a brighter and more opportune future for South Africa. However, we need your support in order to change our country into a nation of hope and for our dream of everyone to live in peace and prosperity to become a reality. To understand our manifesto and views, one needs to understand that the DA does not place people in a position of power according to their race, name or wealth, but rather their talents and efforts. This country cannot move forward without change, and as it stands the unemployment rates and the ever increasing problems are being put aside by the current government for personal ventures such as Nkandla that is surrounded by houses without running water. But dwelling on the negatives and current failures is not our objective. I am here to vie and let you decide that we are working towards a brighter future. it is understandable that people are worried that if they do not vote for the current government that the circumstances of apartheid and a dark past will reappear, but it can be assured that the DA are working towards changing the past and aim for a country that has equal opportunities for all. Our work is evident in the Western Cape where we govern and 76% of the provincial governments budget is spent on poor communities. The Western Capes unemployment rate is the lowest in the country, 12% lower than anywhere else in SouthShow MoreRelated The Role of External Pressure in the Fight Against Apartheid and Minority Rule in South Africa1583 Words   |  7 PagesThe Role of External Pressure in the Fight Against Apartheid and Minority Rule in South Africa External pressure played a very important part in bringing about the end of the apartheid. The embodied rejection of White domination in South Africa, in formations of protests, strikes and demonstrations caused a decade of turbulent mass action in resistance to the imposition of still harsher forms of segregation and oppression. The Defiance Campaign of 1952 carried mass mobilisationRead MoreA better South Africa for the new South Africa Essay625 Words   |  3 PagesA better South Africa for the new South Africa The Apartheid struggle is not an anecdote about a few black people that lived under a suppressive government; it is a story about millions of black people who suffered tremendously under the oppressive classification system of the National Party. It is a story about bloodshed, suffering and tears. It is a story that serves as a painful reminder of the extent that a group of people would go to ensure that the purity of their race was conserved. The ApartheidRead MoreSouth Afric A Nation Of Diversity933 Words   |  4 PagesSouth Africa is located in Southern Africa, it stretches along the South Atlantic and Indian Oceans. South Africa is ranked the 25th largest country in the world by land area and 25th most populated nation. South Africa is the only nation-state named after its geographic location. After the establishment of a constitutional nonracial democracy in 1994, there was an agreement signed not to change its name. It is a nation of diversity. South Africa has 49.32-mi llion people and a variety of culturesRead MoreCome Visit South Africa1217 Words   |  5 Pages South Africa, which is the southernmost country on the African continent, is bordered by the Atlantic Ocean on its west coast and by the Indian Ocean on both south and east coasts. It is renowned for its varied geography, extreme natural beauty, and cultural diversity. All of those attributes make it a desirable destination for travelers. Its neighbors are Namibia in the northwest, Zimbabwe and Botswana in the north, and Mozambique and Swaziland in the northeast. The kingdom of Lesotho forms anRead MoreInterpersonal Cross-Cultural Competencies And Capabilities1376 Words   |  6 Pagescross-cultural competencies and capabilities are critical to the US Army’s strategic objective in the future operating environment. The operational environment requires a holistic view of political, military, economic, social, information, and infrastructure systems. A country’s culture can be defined as a programming of the mind that distinguishes the members of a region or nation fro m another. South Africa has a rich and complex culture and history of its own since its independence from Britain nearlyRead MorePolitical Ideologies2403 Words   |  10 Pagespolitical actions. Its central features are an account of existing power relationships, a model of a desired future, and an outline of how political change can and should be brought about. (2007: 68) This essays main focus will be discussing the main ideologies and focuses of the two leading political parties of South Africa. The African National Congress or ANC and the Democratic Alliance also known as DA. An important insight into both their ideology will be gained by analysing how both partiesRead MoreApartheid and The Future of South Africa in Cry, The Beloved Country1044 Words   |  5 PagesArthur, Napoleon, and Msimangu, all characters from Alan Paton’s book, Cry, The Beloved Country, are used to share Paton’s points of view on the future of South Africa and the apartheid. Paton uses these characters to represent specific views; Arthur expresses clearly that the apartheid isn’t the right way to progress as a country, Napoleon exemplifies how Paton thinks people should take the anti-apartheid effort, and Msimangu explicitly expresses Paton’s ideas of an ideal leader. Arthur JarvisRead MoreSocio-Economic Inequality in South Africa is Due to the Institutionalised Ideological Mismatch Regarding Labour and Economic Policy1665 Words   |  7 PagesSocio-economic inequality in South Africa is due to the institutionalised ideological mismatch regarding labour and economic policy Economic growth is shaped by policy context and promoted most effectively when it is consistent with either liberal market or co-ordinated market ideal type varieties of Capitalism. Policy inconsistency dampers economic growth post-apartheid South Africa attempted to adopt a social-democratic and co-ordinated variety of Capitalism. This failed due to the adoptionRead MoreHardball Essay1203 Words   |  5 Pagessuccessful or not. Having alliances, enemies, and deals is all part of it. In the book â€Å"Hardball: How Politics is Played† written by Chris Mathews explains what it takes to get ahead in politics and how to avoid disasters techniques previously used by others. â€Å"It’s not who you know; it’s who you get to know.† Forming alliances is very important when trying to climb the ladder higher in politics. In 1949 LBJ joined the senate and by the end of 1952 he had won the job of top Democratic leader. Before anythingRead MoreThe Global Economic and Political Implications of the South African 2014 General Elections1164 Words   |  5 Pagesyear for South Africa. The first elections after the death of South African ex-president Nelson Mandela will take place and after twenty years of democracy, the world will be watching us again. The world holds much interest in the economy and politics of South Africa as was discussed in Appendix A and Appendix B and it is safe to assume that the world is a stakeholder in the politics and economy of South Africa. The purpose of this essay is to explore the world’s stake in South Africa, its nature

Forward Contract free essay sample

Suppose that you enter into a six-month forward contract on a non-dividend-paying stock when the stock price is $30 and the risk-free interest rate (with continuous compounding) is 12% per annum. What is the forward price? Problem 5. 4. A stock index currently stands at 350. The risk-free interest rate is 8% per annum (with continuous compounding) and the dividend yield on the index is 4% per annum. We will write a custom essay sample on Forward Contract or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page What should the futures price for a four-month contract be? Problem 5. 9. A one-year long forward contract on a non-dividend-paying stock is entered into when the stock price is $40 and the risk-free rate of interest is 10% per annum with continuous compounding. a) What are the forward price and the initial value of the forward contract? b) Six months later, the price of the stock is $45 and the risk-free interest rate is still 10%. What are the forward price and the value of the forward contract? Problem 5. 12. Suppose that the risk-free interest rate is 10% per annum with continuous compounding and that the dividend yield on a stock index is 4% per annum. The index is standing at 400, and the futures price for a contract deliverable in four months is 405. What arbitrage opportunities does this create? Problem 5. 14. The two-month interest rates in Switzerland and the United States are 2% and 5% per annum, respectively, with continuous compounding. The spot price of the Swiss franc is $0. 8000. The futures price for a contract deliverable in two months is $0. 8100. What arbitrage opportunities does this create? Problem 5. 27. A stock is expected to pay a dividend of $1 per share in two months and in five months. The stock price is $50, and the risk-free rate of interest is 8% per annum with continuous compounding for all maturities. An investor has just taken a short position in a six-month forward contract on the stock. a) What are the forward price and the initial value of the forward contract? b) Three months later, the price of the stock is $48 and the risk-free rate of interest is still 8% per annum. What are the forward price and the value of the short position in the forward contract?