The Enthalpies of Combustion Essay Example for Free

The Enthalpies of Combustion Essay Standard enthalpy change of combustion is the energy change that occurs when 1 mol of fuel is completely burnt in oxygen under standard conditions. However, it is impossible for substances to be burnt under standard conditions. The enthalpies of combustion are different depending on the number of carbons and hydrogens in each substance. For example, the enthalpy combustion for methane is -890 kJ mol-1, however the enthalpy change of combustion for ethane or propane will be greater because more bonds are involved and therefore more bonds are broken and made. All combustion reactions are exothermic because energy is given out to make bonds. Figure 1: Exothermic reaction Before you start doing calculations for enthalpy change of combustion you firstly need to balance the equation. For example: Methane CH4 (g) + 2O2 (g) 2H2O (g) + CO2 (g) Also it is important to note when making a combustion reaction balanced equation that the state symbols for all the substances are gaseous even water. Moreover, it is only in a combustion reaction that you use halves in an oxygen molecule. An example for octane is: C8H12 (g) + 12.5O2 (g) 8CO2 (g) + 9H2O (g) Method for the enthalpy of combustion for various alcohols 1. Set up a tri pod and place tiles around it. 2. Fill up a metal calorimeter with 200 cm3 of water and place on the tri pod. Also, place a thermometer on the container. 3. Record the reading on the thermometer of the temperature of the water. 4. Weigh the spirit burner containing the alcohol you are going to use and again record the reading. 5. Place the spirit burner containing the alcohol under the tri pod and quickly as possible take the lid off and light a match on it. 6. Wait till you will see a 15 degree increase on the thermometer. 7. When you see a 15 degrees increase, place the lid back on the alcohol and stir the water well with the thermometer until you see there is no change in temperature. 8. Weigh the alcohol and record the reading. Also record the reading of the temperature after it has increased. 9. Repeat steps 1-8 for all different alcohols. Results obtained from experiment Methanol Ethanol propan-1-ol Butan-1-ol Pentan-1-ol Enthalpy change of combustion (kJmol-1) 379.80 1071.23 1332.62 1715.82 2110.04 Enthalpy change of combustion = (1/moles of alcohol burned) x enthalpy released during the ex. True results of alcohols that should be obtained Methanol Ethanol propan-1-ol Butan-1-ol Pentan-1-ol Enthalpy change of combustion (kJmol-1) -890.30 1559.70 2219.70 2876.50 3509.10 From the results I obtained I can make a conclusion that the results were not very close to the true, this is because the experiment could not done under standard conditions like the other and therefore because of that some heat was lost to the surrounding. While I was carrying the experiment I realised that a black substance began to form underneath the colorimeter (container where the water was put in and heated up) which was carbon, meaning there was incomplete combustion. This therefore effected the results I obtained because the combustion experiment was not complete. Evaluation Experimental errors In any experiment, errors are made which are unavoidable. We can work out the errors of the equipments that were used in the experiment to find out which has the most effect. It is then best to convert these errors in to percentages because it is easier to see which has the most effect on your results and which has the least percentage error. Percentage error = error / reading x 100. A balance has a precision error of 0.005. Next I will turn it to a percentage error. The balance was used to weigh the spirit burners of the 5 alcohols before using it in the experiment and after it was used to heat the water up. Methanol Ethanol propan-1-ol Butan-1-ol Pentan-1-ol Initial mass of spirit burner / g 198.56 188.80 180.66 212.75 189.62 Percentage error/ % 0.003 0.003 0.003 0.002 0.003 Methanol Ethanol propan-1-ol Butan-1-ol Pentan-1-ol Final mass of spirit burner / g 197.41 188.16 180.09 212.08 189.08 Percentage error / % 0.003 0.003 0.003 0.002 0.003 Looking at the results above for the percentage errors, I can conclude that the balance did not effect the results I obtained as it gave me a small percentage error that was less than 1%. This ensures me that the measurements of the spirit burners that I obtained using the weighing balance where very accurate. Procedural errors * A thermometer was placed on the colorimeter and when reached to 500c and recorded the highest temperature by siring until there was no increase in temperature. * Keep lid on spirit burner to endure the alcohol did not evaporate to obtain a accurate measurement of the mass of alcohol combusted. * Draft exclusion made using insulating tiles. This is so less heat and temperate near the spirit burner that is lighted is relatively kept constant and not effected by air coming from window or heat from radiator.

The Changing Meaning of The Taming of The Shrew Essay -- Shakespeare T

The Changing Meaning of The Taming of The Shrew    Through the ages, it is common for words to change in meaning. As the world around us changes, words often take on new meanings to accommodate the changes in lifestyle and society caused by progress. Thus, it is easy to become confused when reading literature that was written several centuries before, since the very same words may hold varying significance. In "The Taming of the Scold," D.E. Underdown offers background information which makes Shakespeare's The Taming of The Shrew much more understandable in terms of the discordant ideas on women in society in different time periods. The Taming of the Shrew has a much different effect on contemporary readers than it may have had on 16th century readers, since the world has changed and society is vastly metamorphosed. When Shakespeare wrote The Taming of the Shrew, it was widely known that women should be subservient to their husbands. Today, however, in America this notion seems ludicrous. After the feminist movement, the fight for equality, women have gained much more liberty and respect than they once had. With the increased liberty, it is difficult to seriously consider how women were once treated as possessions. Because of the incongruity in views of the two eras, pieces like Underdown's "The Taming of the Scold" are crucial to a modern understanding of literature that deals with archaic social norms, chiefly since it puts the literature into the context of its creator's social mentality. Through Underdown's piece, I was able to achieve a much better understanding of the significance of Petruccio's "taming" o f Kate in the examples which explain the common practices and occurrences of the age. Kate experienced a chariv... ...low the direction of their leaders or rulers. Through explaining the relationship between the family and society, Underdown divulges the intent with which Shakespeare wrote the play. In Kate's surrendering to Petruccio, Shakespeare maintains familial and social order. Since words and the meaning or ideas behind them change over time, it is important to be able to put the literature into social context in order to derive from it its full meaning. Underdown addresses many issues in "The Taming of a Scold" which are relevant to Kate and Petruccio's behavior that are not known or understood today. Pieces like Underdown's serve as a bridge between two eras - the one in which the story was read and the one in which it was written. With the assistance of such pieces, it is possible for one to gather a much better understanding of the writer's meaning in the story.   

Grendel and Frankenstein Essay

Grendel, the main character in the novel Grendel by John Gardner, and the Monster, the main character in the novel Frankenstein by Mary Shelley are both consumed by the desire to discover the nature and secret of human life. They are both monsters and so both are outsiders in the world of humans, but they try to integrate themselves into the society, only to be shunned universally. Their nature of monstrosity lies at the center of the action since they are being rejected by the society. Their response to this rejection paves the way to the discovery of human nature. Grendel the monster has an ambiguous characterization. Although he displays nothing but the most primitive human qualities with the strong evidence of his irrational outburst of emotions and brutalities, he has an extraordinary inquisitive nature with his capability of temperament and rational thoughts. Shelley’s Monster in the Frankenstein has also a temperament and benevolent nature but as he experienced man’s brutalities and judgmental nature due to his ugly physical appearance, his violent tendencies has been revealed. He starts to take revenge in his creator who is scientifically responsible to his existence and unfortunate fate. Shelley’s monster unlike Grendel is not presented ambiguously since he is only in search of happiness through companionship while Grendel is in search to answer his philosophical question whether human life and created patterns have meaning at all. During his younger years in the initial part of the novel, Grendel spends his life innocently, exploring his confined world in the caves with his mother, untroubled by the outside world of philosophical questions. I understood that the world was nothing: a mechanical chaos of casual, brute enmity on which we stupidly impose our hopes and fears. I understood that, finally and absolutely, I alone exist. All the rest, I saw, is merely what pushes me, or what I push against, blindly—as blindly as all that is not myself pushes back (Howell 67). Grendel in this statement initially sees the world as mindless without any discernible plan and reason. He believes any attempt to make a meaning or pattern in the world is a misguided effort. But one day, the young Grendel finds himself in a lake full of fire snakes, and he swims through it until he reaches the human world and civilization on the other side. Grendel’s inevitable decision to cross the lake is the start of his life towards adulthood. He starts to observe the world of men. Grendel finds the nature and lifestyle of men as pleasurable and enjoyable experience. Shelley’s monster on the other hand reveals his good side in the initial part of his existence but as he discovers the judgmental side of human being, who judges according to physical appearance, he starts to rebel putting all the blame to his creator. Grendel and Shelley’s monster, though both has monstrous nature and though both experience man’s brutality due to the fact that they are monsters, perceive human life differently. Grendel sees the world with fascination while Shelley’s monster perceives the world with contempt. Grendel is fascinated and at the same time envies how has mankind successfully evolved from a nomadic and tribal culture into a culture of obligations as they create government and institutions due to their continuous desire for material prosperity. He admires the intellectual capability of men and marvels at how they create roads, military, and government. Grendel therefore inevitably thinks whether life has meaning or not and whether human actions and efforts are senseless or meaningful. Since he cannot form philosophical ideas that explain his observations of human life, he decides that human efforts and created patterns are wasteful. Moreover, Grendel decides that it does not matter whether he will eat or kill people. But through his observations of Hrothgar of the Dane, the most powerful king of the area who sings about men’s glorious life and history, Grendel starts to perceive that human life is so rich that he wants to be a part of it. Grendel conspicuously wants to be part of human life. He believes that he can understand the nature of human beings more than he understands the monsters in the deep cave. Grendel delights in humans’ sense of community, intellectuality and their illusionary perspective towards life. Grendel sees that he belongs in human community because like him human beings are in continuous search of meaning. Shelley’s monster on the other hand who is product of collaborative scientific work and supernatural workings and who is strongly rejected by the society, approaches his situation with contempt. His monstrosity is not only reflected in his grotesque appearance but also in his dark tendencies to be evil after he is rejected. The dragon in the story, however, tells Grendel that the human world is actually meaningless and empty. The dragon has a logical belief that nothing man creates—religion, government, literature, poetry, philosophy, and so on—will survive the destruction of time and therefore approaches all man’s endeavors as something pointless and ridiculous. In addition, the dragon insists that Grendel can take and eat whatever he wants since morality is pointless anyway. Grendel sees the logic of this belief, but part of him yearns for men’s appealing endeavors and pursuits. Grendel wants to escape his brute and mechanical place in the caves that follow no meaningful and universal pattern. The animals and monsters that surround him in cave are dumb and undignified, and this continually frustrates him. However, the concept of community, civilization, and human language that share a common meaning in the human world somehow comforts Grendel. Grendel wants to be part of the human world even though he will be forever trapped in the role of a villain. Although Grendel knows that the beautiful concepts like religion, philosophy, government, and so on are just human projections to overcome their chaotic world, he still wants to be part of it. Apparently, Grendel is torn between his mother’s very animalistic nature, the generally moral and humane world of the Danes and the seemingly logical beliefs of the old Dragon. Grendel is stranded on what he knows to be true and what he wishes is true. However, these differing and conflicting philosophies leave Grendel confused and angry throughout his violent and isolated life in the novel. Grendel and Shelley’s monster are both lonely in the same manner but in different situation. Grendel has a family in the deep cave but he can not accept their totally animalistic and undignified nature, who solely satisfies themselves in physical survival alone and not in intellectual growth. Apparently, Grendel is ashamed in his lineage. The monster in Shelley’s novel on the other hand is the only one of its kind. He is literally alone. His simple desire is to have a companion, someone who will understand his grotesqueness. But nonetheless they both desire to be part of human life even though humans detest and fear them. Both monsters see themselves in human beings– they have the capacity to be good and to be evil. Moreover, human beings has the possibility to satisfy their desire not to be alone. Unlike Grendel, the character of the monster in the novel Frankenstein is not torn between differing philosophies but instead his actions are motivated by revenge because human beings base their treatment on him according to his physical grotesqueness and ugliness and not on his initial gentle and kind nature. His ugly outward appearance is rewarded by beatings and disgust. As he tries to integrate himself in the society, he is shunned universally. Thus, the monster seeks revenge on Victor for making him so hideous and rendering him permanent loneliness because of his ugliness. However, the monster offers Frankenstein peace in exchange for a companion of like origin, but when Frankenstein does not follow, he vows to destroy him and so begins killing off Frankenstein’s intimate friends and loved ones—the people the monster most envies because he does not have them. When Victor dies due to remorse and disillusionment, the monster feels both joy and sadness—joy because Victor is the very cause of his suffering, and sadness because his creator is the only person with whom he has had any sort of relationship. â€Å"I, the miserable and the abandoned, am an abortion, to be spurned at, and kicked, and trampled on†, this statement from the monster as he sees his creator died reflects his retrospection to his suffering and aloneness (Shelley 268) . He is like an aborted child, left and unloved. The monster is feverishly created or fashioned by Victor Frankenstein who studied natural philosophy and chemistry, immersed himself in research, and became eventually consumed by the desire to discover the secret of human life—out of old body parts. After seeing and realizing the monstrosity he has created, Victor flees as the sight of his creation strongly horrifies him. Victor runs and wanders in the streets with remorse. He immediately perceives his creation as a purely evil being and therefore establishes an unmitigated hatred for it. When Victor returns to his apartment, the monster is gone. Victor is apparently the one responsible in the existence of the monster and the society as the one who provoke the monster’s evil tendencies. In the story of Grendel on the other hand, the shaper and the dragon are the one who provoke Grendel’s philosophical quest towards human life. The dragon, who provides the impression of the world as essentially meaningless and empty, and the shaper, who provides an image of the world as essentially connected and purposeful-an image that Grendel finds incredibly seductive, motivates Grendel’s actions on earth, whether good or bad. Apparently, the novel centrally illustrates the corrupting effects of man’s pursuit of knowledge and modern technology. Frankenstein, the main character of the story, created life from dead parts in his desire to help mankind conquer diseases and death, but when he finally finished the act of creation and saw its implications and ugliness, he turned away from the monstrosity he created. Hence, this novel basically demonstrates the horrifying effects of the careless use of science. In many ways, the book reflects the era when it was written—the period of Industrial Revolution during the 18th century, when major initial and dramatic changes took place in science and technology. While the novel Grendel subtly reflects the world during the period of Romanticism– where people are in the period of intense philosophical quest and when poetic and artful words and stories are powerful. In the story, Grendel finds Shaper’s art, language and imagination so seductive that he wants to be part of it. The stories he hears are tried to be applied—philosophy, government and poetry—and therefore he is affected not only by stories and words he hears, but also by stories that exist outside his own experience. In the novel Frankenstein, Shelley seems to stress the limits of human capacity. She gives the readers an idea about the extent of human ignorance in terms of man’s relationship with his creator. The character of Frankenstein in this novel is dominated by the power of human reason through technology and science instead of faith in God. When one believes in the existence of a Supreme Being, he or she is likely to recognize the limitations of human nature. However, in this novel, Frankenstein attempted to create a human being that is better than the existing creation: â€Å"He wanted to find the secrets of life so that all people could live without fear of death†¦Ã¢â‚¬  (Shelley 7). Thus, this story somehow illustrates some of the shortcomings of the contemporary world in the midst of modernity in science. Although Shelley considers the fact that scientific experiments are for the sake of humanity, these experiments have the potential to destroy them as well. Hence, through the novel, Shelley shows that, by being ignorant of the consequences of creating something new and superior, the entire race may be jeopardized and be destroyed by the same creation. Frankenstein’s process of creation contrasts with God’s creative and redemptive process of creation. In the novel Grendel however focuses not so much on physical creation but on the philosophical aspect of human life. It explores the question whether â€Å"created patterns† has meaning at all. Does the meaning comes from the execution and its effects or does it completely lie on how people perceive its meaning? In addition to the novel Frankenstein, the author highlights the incompetence of humans in attempting to play â€Å"God. † Human’s knowledge is sometimes used that will destroy them eventually in the end. For instance, Frankenstein’s arrogance in playing â€Å"God† for his attempt to create life resulted in the death of his friends and family. This caused him to be consumed in grief and guilt as he endured the terrible loss of friends and family who died by his own hands. The story of â€Å"Frankenstein† can be read as a timeless tale of warning. Like Frankenstein, some contemporary scientists make it their goal and purpose to study and understand the unknowable and to improve our standards of living. However, critical foresight and moral considerations are more significant than faith in science. The novel is a perfect illustration of how a scientist should not be. Knowledge affects humanity in a more complex way. Human miseries and life’s complexities can be caused by humans’ obsession in the pursuit and application of knowledge. Shelley in this novel seems to highlight modernity as an apparent political and social attitude during the time of industrialization where science was attempting to unconsciously alter the traditional way of living. Grendel novel however strongly highlights how language and poetic words affects human pattern of thoughts. When Grendel comes to the world, he is torn with opposing ideas whether life is meaningful or senseless. Both the character of Frankenstein and the Monster , considering their actions in the course of the novel, are symbols of darkness, chaos, and death. Though both Grendel and Frankenstein committed numerous acts of violence and cruelty in the stories, the writers manage to elicit sympathy from the readers that leads the readers to consider them as heroes. The writers portray them as both victims who only want and desire companionship and community that human beings experienced. Both writers present their main characters as monsters but with the same need as that of men. Work Cited: Howell, John Michael. Understanding John Gardner. California: Univ of South Carolina Press, 1993 Shelley, Mary Wollstonecraft. Frankenstein: Or, The Modern Prometheus. New York: Plain Label Books, 2002

A Midsummer Night s Dream Opera - 883 Words

Andrew Muckle Professor Boots 15 April 2016 A Midsummer Night’s Dream Opera On Saturday April 16th, I attended A Midsummer Night’s Dream, an opera by Benjamin Britten at Boston University. I have never been to an opera before, so I went in wondering if I would enjoy it as much as I enjoy the orchestra. I read a review by Gillian Daniels who said â€Å"It’s an opera faithful to the spirit of its material† having me go in with somewhat high expectations (Daniels). I walked into a fairly large theater with three friends waiting for the play to begin. We took our seats that were four rows from the front of the balcony I felt that our seats were pretty good since we were more or less close to the stage. The lights finally dimmed and the opera began.†¦show more content†¦Because of this, all vowels sung â€Å"in full voice all sound the same.† (Highfield). The mood created by the back stage and production staff made a tremendous impact on the performance. I found that the lighting was very well done; creating the feel of a gloomy dark forest that would exist in a dream. Some of the sets were basic but very well prepared. I was impressed how their simplicity more than accomplished their purpose, and when the scenes changed their austerity allowed the movement to be very seamless and unobtrusive. I believe Daniels was right in saying that â€Å"This vision is every bit the dream of the title.†(Daniels) The opera A Midsummer Night’s Dream by Benjamin Britten did seem very distinctive in the way it was presented compared to the movie by Michael Hoffman. The characters were dressed, in my opinion, fairly differently from the movie. The scene between Oberon and Titania was largely the same in storyline, but the look, as well as the dialogue didn t seem similar to the movie. Perhaps having to read the dialogue from the teleprompters made a difference versus listening to the dialogue in the film. In the movie, the fairies all seem to be very roman in the way they were dressed. They also had normal human bodies. In the opera however the esthetic seemed somewhat different.