To Determine the Heat of Formation of Calcium Carbonate Essay Example for Free

To Determine the Heat of Formation of Calcium Carbonate Essay A) In the 1st part, an accurately weighed known mass of anhydrous magnesium sulphate(VI) powder is added to known volume of deionized water. With the help of the data of temperature change during the addition, the molar enthalpy change of solution of anhydrous magnesium sulphate(VI) can be calculated. ( H1) B) In the 2nd part, an accurately weighed known mass of magnesium sulphate(VI)-7-water powder is added to known volume of deionized water. With the help of the data of temperature change during the addition, the molar enthalpy change of solution of magnesium sulphate(VI)-7-water can be calculated. ( H2) After that, by constructing a suitable enthalpy cycle, i.e. MgSO4(s) + 7H2O(l) MgSO4 . 7H2O(s) MgSO4(aq) and applying Hesss law, the molar enthalpy change of hydration of magnesium sulphate(VI) ( H) can be calculated. ( H = H1 H2) 5) Data: Anhydrous MgSO4(s) MgSO4(s)-7-water Molar mass / g mol-1 120.4 246.4 Mass of copper(II) sulphate / g 3.01 6.16 Initial temp. of water / oC (T1) 25 24 Highest/Lowest temp. attained / oC (T2) 34 22.5 Change in temperature / oC (T2-T1) +9 -1.5 Volume of deionized water used: 100 cm3 6) Calculation: The molar enthalpy change of solution of anhydrous magnesium sulphate(VI) = mc T x (no. of mol)-1 = (100 x 4.2 + 3.21 x 1.3) x (-9) x (0.025)-1 = -152.70 kJ mol-1 The molar enthalpy change of solution of magnesium sulphate(VI)-7-water = mc T x (no. of mol)-1 = (100 x 4.2 + 3.21 x 1.3) x (1.5) x (0.025)-1 = 25.45 kJ mol-1 By Hesss law, H = H1 H2 = -178.15 kJ mol-1 The molar enthalpy change of hydration of magnesium sulphate (VI) = -178.15 kJ mol-1 Discussion: (1)~(3) is answered above 4) What assumption have you made in your calculation? Assumed: * The thermal capacity of the beaker is negligible. * The specific heat capacity of the 2 resulting solutions are the same as water, and they also weight 1 g/cm3 * The weight of the solids which dissolved in deionized water does not affect the total mass of the solution. * The solids are in pure state. * The solid are dissolved quickly so that the heat losses are negligible. * The resulting solutions were infinitely diluted, that is further addition of water would not cause any further heat change. * There was no heat lost to surrounding in 1st part and no heat gained in 2nd part. 5) What are the sources of error in this experiment? * The specific heats of the solutions cannot be exactly 4.2 J g-1 oC-1 as that of water. The error could be minimized by using electrical compensation method. * The solid night not be in pure state, that was, the anhydrous magnesium sulphate(VI) may be completely anhydrous, which could be improved by heating the sample for several hours in an oven and then use immediately. * Some solid might not dissolve quickly enough and thus heat was lost. The improvement was using the reactants in powder form or tiny crystal form abut not bigger one, such that they could be dissolved quickly enough. * Some heat might e lost to 1st part or gained in 2nd part. The improvement was insulate the beaker or use a vacuum flask calorimeter. 6) Why cannot the molar enthalpy change of hydration of magnesium sulphate(VI) be measured directly in the laboratory? Because it was not possible to form magnesium sulphate(VI)-7-water from anhydrous magnesium sulphate(VI) and water because the anhydrous saly may dissolved in water instead. Conclusion: By using the experimental result, the molar enthalpy change of hydration of magnesium sulphate(VI) is -178.15 kJ mol-1

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A characteristic property can help identify a substance. A characteristic property will never change even when the volume of a substance is varied. A characteristic property also does not change when a substance changes state in matter. A physical property cannot identify a substance. A physical property will change when the volume of a substance is varied. It can also change when the substance changes state in matter. For example, if the volume and mass of a substance changes then the physical appearance will also change. However, the density, which is a characteristic property, will not change at all. The boiling point of a substance is the temperature that a substance changes from a liquid to a gas. The boiling point of a substance is a characteristic property because the boiling point of a substance will never change even when the volume and mass changes. The only thing that will change is the time that it takes to reach that temperature. If the mass and volume of the substance is small, then it will take a small amount of time for the substance to reach the temperature. However if the mass and volume of the substance is larger, then it will take a longer time to reach the temperature. The purpose of this lab was to see if when the volume of a substance changes so does the boiling point. The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The hypothesis was accepted. The hypothesis was if the am... ...roup seven had were that day one plateaued at a lower temperature than day two. It was learned that changing the volume of the same substance will never change the boiling point of the substance. However having two different substances with the same volume will result in two different boiling points. The purpose of this lab was to determine if changing the volume of a substance will change the boiling point. This is useful to know in real life because if someone wanted to boil water to make pasta and did not know how much water to put in the pot. If the person knew if changing the volume of a substance will not change the boiling point, but only alter how much time it takes for the substance to reach the temperature. Then the person would know that it would be better to not put too much water in the pot, because it would take longer for the water to boil.

Dulce Et Decorum Est And The Soldier

Dulce et decorum est is written regarding the First World War in the hindsight of the battle of the Somme. This takes a somewhat cynical view on warfare. The soldier by Rupert Brooke on the other hand takes a very strong patriotic feel and this shines through more then anything else. The soldier paints a picture of English serenity and whereas â€Å"dulce et.† portrays Owens anger at the indifference of those at home who continued to propagate lies. You can see the influence of Siegfried Sassoon in this piece. The language is more direct and shocking â€Å"guttering, choking, drowning† helps convey the grievance in the air. In the soldier the language is less deplorable and has a feel more of a love poem â€Å"her sights and sounds†¦ under an English Heaven† this coupled with the fact that the poem is written as a sonnet reiterates the feel of Love. Both poems are based on death in Wars. However Brooke paints a more glamorised and less direct picture of death â€Å"if I should die, think only this of me: That there's some corner of a foreign field†¦blest by suns of home.† This evokes the idealistic image of a perfect England in a ‘Golden' age, such as many believe existed immediately prior to the First World War. This does however expose the arrogance that Brooke perhaps had. It places too much importance on his own sacrifices and not on the general sacrifices being made by so many, and on the loss of a way of life, which the war would bring out like many other First World War poets such as ‘Edward Thomas' and ‘Charles Hamilton Sorely'. Owen on the other hand almost haunts the reader using fiery vocabulary to help depict the shocking death of a soldier â€Å"guttering, Choking, Drowning.† Owen clearly wanted to address the people at home and suggests to them that if, in their worst nightmares, they could re-live this experience, they would not keep repeating that it is good and sweet to die for your country. He is saying that no one who has witnessed these horrors could ever encourage anyone to take part in such a war. He had already pointed out the exhaustion of the soldiers â€Å"drunk with fatigue; deaf even to the hoots† helping the reader to visualise the lack of awareness of the soldiers. This certainly will give the reader a much more negative take on the war contaray to the over-hyped propaganda war that those at home believe. Brooke conveys the image that was painted by the media in Britain at the time of the war and even in death, he believes he cannot remove that sense of pride from him and his passing will not be in vain if, at home in England people are, once again happy and at peace. He feels that by his death he will have given back to England everything, and more, that it gave to him. The happiness and security earned by his sacrifice will buy his eternal peace † this heart, all evil shed away, A pulse in the eternal mind† Owen continues his cynicalism of the war in the last verse using necessarily harsh and wicked language â€Å"come gargling from the froth-corrupted lungs†. They fling the man into a wagon, because they know there is no point in being gentle- he will soon be dead anyway. The description of his face and eyes â€Å"And watch the white eyes writhing in his face† gives him a ghost-like quality. This verse is intended to demonstrate the realism of a violent, u nnecessary death; hence it builds to a crescendo of anger, before a final earnest plea to stop the lies. These two poems could be no more different. ‘The soldier' is a poem supporting the war in a way not too dissimilar to the way the media in that time promoted it whilst ‘Dulce Et Decorum Est' is a pessimistic take on a war that was conveyed by the British media as far from the truth as possible. Owen wanted the British people to know the truth about the war and expressed these feelings best in his poetry. Brooke in contrast went along with the glamorized image that had been portrayed by the media, which wasn't a fair reflection on the war.

Essay about Company of Wolves-Little Red Riding Hood

Little Red Riding Hood â€Å"The Company of Wolves† by Angela Carter is very similar to â€Å"Little Red Riding Hood†, the little girl heading out with a basket full of liquor and goodies for her grandmother. The wolf stopping her on her way to the grandmother’s house; the wolf races to the house, eats the grandma, pretends to be the grandma and makes â€Å"Little Red Riding Hood† believe that he is her grandma. He pounces on her and tries to eat her but a hunter comes and kills the wolf and saves the grandma. The story reveals an extensive imagination by elaborating on different ideas and points of view of gender roles. Carter’s characters portray these roles very similar to the way we view gender roles today. Carter uses the wolves as a†¦show more content†¦We could assume that every wolf was once a man. At the beginning Carter explains how wolves are â€Å"carnivore incarnate and he’s cunning and ferocious†, but yet she also explains how †Å"melancholy† a wolf can be because â€Å"the beasts would love to be less beastly if only they knew how† (110, 112). Everyone seems to be afraid of these wolves â€Å"fear and flee the wolf; for, worst of all, the wolf may be more then he seems† which could mean that the wolf isn’t necessarily after fresh meat but that he just wants sex. The wolf only sees women as meat. It kind of reminds me of â€Å"The Wedding Singer† where Glenn grades his women with the FDA system, for example if he thought a woman was top of the line he would say that she was Grade A, top choice meat. At the end of the story, the wolf seems to be put in his place by the girl because she doesn’t fear him and when he tries to frighten her with telling her he’s going to eat her, she just laughs at him and rips off his clothes. Many stereotypes have men portrayed as beasts that crave sexual encounters and as creatures that only think about sex which Carter seems to do with the wolves. Women are seen as innocent and virtuous individuals that are only spoiled by men. Bibliography Carter, Angela, The Company ofShow MoreRelatedAngela Carter Essay1009 Words   |  5 Pageswerewolf’ and ‘The Company of Wolves’ as appropriations of the traditional ‘Red Riding Hood’ story. Carter used language, atmosphere and originality twisted with a sense of tradition, which has created two amazingly deep stories. We know these are appropriations of the traditional red riding hood story, as they contain the somewhat traditional aspects/storylines of the traditional story but they are in one way or another completely different. Carter appropriated Little Red Riding Hood in a dark and deepRead MoreEssay on Gender Roles in Angela Carters The Company of Wolves820 Words   |  4 PagesGender Roles in Angela Carters The Company of Wolves In her transformation of the well-known fable Little Red Riding Hood, Angela Carter plays upon the readers familiarity. By echoing elements of the allegory intended to scare and thus caution young girls, she evokes preconceptions and stereotypes about gender roles. In the traditional tale, Red sticks to the path, but needs to be rescued from the threatening wolf by a hunter or woodsman. Carter retells the story with a modern perspectiveRead MoreLittle Red Riding Hood Isnt so Nice After All793 Words   |  4 PagesAll In the story of â€Å"Little Red Riding Hood and the Wolf†, Roald Dahl interprets the little girl as a gun-wielding murderer. While in most of the other interpretations of this story we’ve read this semester, she seemingly is just a young and naive little girl. 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In ‘The Bloody Chamber’ Angela Carter effectively draws out the theme of feminism byRead MoreZipess View on Fairytales1975 Words   |  8 PagesIn this essay, I examine what Zipes means by institutionalised, define what makes a fairy tale and evaluate how different versions of Little Red Riding Hood reflect the social ideology of the period. Zipes is not using ‘institutionalised’ in the traditional, negative sense of being rigid and never evolving. He theorises that fairy tales have become part of the social psyche. They permeate into every aspect of the social unconscious to become meme, examples of which are ‘tunes, ideas and catchphrases’Read MoreThe True Benefits Of Wolves1622 Words   |  7 Pagescenturies, wolves have been regarded as the enemy. Whether from fairy tales like the three little pigs, to little red riding hood, people constantly loathe them. Why is this? You see, it is human nature to look for a common enemy. Unfortunately, wolves are seen as that enemy. Nevertheless, despite the negative images in the media and mass wolf culls, they keep on persisting. By killing wolves, we are damaging our environment and disrupting the natural cohesion that has been established between wolves andRead MoreEssay on The Variations in Little Red Riding Hood3614 Words   |  15 PagesThe Vari ations in Little Red Riding Hood Fairy tales are under attack in the United States from both right- and left-oriented pressure groups. (Ravitch, 62-96) From the left, the charges include sexism, stereotyping, distortion, and anti-humanism. (Ravitch, 84) From the right, the charges include immorality and objections to the portrayal of violence, death, and the supernatural. In addition, some critics claim that the tales terrify their children. (Ravitch, 76). In The Language Police, DianeRead MoreIn the short stories in ‘The Bloody Chamber’, Carter is excessively interested in violent instincts’. How far do you agree with this view?967 Words   |  4 Pagesher short stories. Carter appears to be excessively interested in violent instincts because she wanted to explore the human nature. In the Company of Wolves, the narrator addresses the reader, from the perspective of someone involved in the story In ‘granny’s bed between the paws of the tender wolf’ suggests that this story is based on little red riding hood. The juxtaposition of tender and wolf, shows how Carter creates dominant male characters which though are presented as evil are also seen to