Coffee Cup and Bomb Calorimetry

A calorimeter is a device used to measure the quantity of heat flow in a chemical reaction. Two of the most common types of calorimeters are the coffee cup calorimeter and the bomb calorimeter. Coffee Cup Calorimeter A coffee cup calorimeter is essentially a polystyrene (Styrofoam) cup with a lid. The cup is partially filled with a known volume of water and a thermometer is inserted through the lid of the cup so that its bulb is below the water surface. When a chemical reaction occurs in the coffee cup calorimeter, the heat of the reaction is absorbed by the water. The change in water temperature is used to calculate the amount of heat that has been absorbed (used to make products, so water temperature decreases) or evolved (lost to the water, so its temperature increases) in the reaction. Heat flow is calculated using the relation: q (specific heat) x m x Δt Where q is heat flow, m is mass in grams, and Δt is the change in temperature. The specific heat is the amount of heat required to raise the temperature of 1 gram of a substance 1 degree Celsius. The specific heat of water is 4.18 J/(g ·Ã‚ °C). For example, consider a chemical reaction that occurs in 200 grams of water with an initial temperature of 25.0 C. The reaction is allowed to proceed in the coffee cup calorimeter. As a result of the reaction, the temperature of the water changes to 31.0 C. The heat flow is calculated: qwater 4.18 J/(g ·Ã‚ °C) x 200 g x (31.0 C - 25.0 C) qwater 5.0 x 103 J The products of the reaction evolved 5,000 J of heat, which was lost to the water. The enthalpy change, ΔH, for the reaction is equal in magnitude but opposite in sign to the heat flow for the water: ΔHreaction -(qwater) Recall that for an exothermic reaction, ΔH 0, qwater is positive. The water absorbs heat from the reaction and an increase in temperature is seen. For an endothermic reaction, ΔH 0, qwater is negative. The water supplies heat for the reaction and a decrease in temperature is seen. Bomb Calorimeter A coffee cup calorimeter is great for measuring heat flow in a solution, but it cant be used for reactions that involve gases since they would escape from the cup. The coffee cup calorimeter cant be used for high-temperature reactions, either, because they would melt the cup. A bomb calorimeter is used to measure heat flows for gases and ​high-temperature reactions. A bomb calorimeter works in the same manner as a coffee cup calorimeter, with one big difference: In a coffee cup calorimeter, the reaction takes place in the water, while in a bomb calorimeter, the reaction takes place in a sealed metal container, which is placed in the water in an insulated container. Heat flow from the reaction crosses the walls of the sealed container to the water. The temperature difference of the water is measured, just as it was for a coffee cup calorimeter. Analysis of the heat flow is a bit more complex than it was for the coffee cup calorimeter because the heat flow into the metal parts of the calorimeter must be taken into account: qreaction - (qwater qbomb) where qwater 4.18 J/(g ·Ã‚ °C) x mwater x Δt The bomb has a fixed mass and specific heat. The mass of the bomb multiplied by its specific heat is sometimes termed the calorimeter constant, denoted by the symbol C with units of joules per degree Celsius. The calorimeter constant is determined experimentally and will vary from one calorimeter to the next. The heat flow of the bomb is: qbomb C x Δt Once the calorimeter constant is known, calculating heat flow is a simple matter. The pressure within a bomb calorimeter often changes during a reaction, so the heat flow may not be equal in magnitude to the enthalpy change.

Suicide Is The Leading Cause Of Deaths Of Adolescents

Suicide is the leading cause of deaths of adolescents in Australia. In 2005, it was estimated that deaths caused by suicide was accounted for one- fifth of deaths among teenagers (Life communications, 2012) in 2012 it was estimated that 1,901 (16.8 per 100,000) males and 634 females (5.6 per 100,000) lives were lost due to suicide, which roughly calculates to seven deaths a day that’s caused suicide (Lifeline, 2010) and those who committed suicide seventy five percent were males while the other twenty five percent were females. In Australia between 2009 and 2013 the highest suicide rates among the adolescent male and females were found in the Northern Territory (17.6 per 100,000) then Tasmania (14.0 per 100,000) followed by Western Australia (13.4 per 100,000, Queensland (13.3 per 100,000), South Australia (11.9 per 100,000), Victoria (9.4 per 100,000), Australian Capital Territory (9.1 per 100,000) lastly New South Wales with the lowest suicide rates in Australia (9.1 per 10 0,000) (Hunter Institute of Mental Health, nd). This essay will look at the common sense view, sociological imagination, social causes and factors that contribute to and eventually lead to youth suicide in Australia, and the functionalist theorist point of view. Adolescents that commit suicide are immediately presumed to have one or more mental illness such as depression or bipolar disorder and also assumed to have shown many signs that they were having thought suicidal thoughts, however in most casesShow MoreRelatedThe Suicide And Suicide Prevention1534 Words   |  7 PagesSuicide is defined as death by an act of self-infliction as an effort to end one’s life. According to the Centers for Disease Control and Prevention (2013), suicide was the tenth leading cause of death for all ages among Americans in 2013. It is the second leading cause of death among fifteen to twenty-nine year olds globally stated by World Health Organization (2015). Suicide being ranked that high on the lists of causes for deaths is astonishing because each of those deaths was preventable.Read MoreThe Link Between Adolescent Depression And Suicide823 Words   |  4 Pages Is There a Link Between Adolescent Depression and Suicide? 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Based on the results, it is determined that stress-Read MoreSuicide Is The Third Leading Cause Of Death1191 Words   |  5 Pages Suicide is the Third Leading Cause of Death in Adolescence Connie Yonn West Coast University Suicide behavior arise in adolescence, a period when significant mood and disturb behavior preoccupied with death (Stoep, 2009). Teen suicide rates are disturbing and have been increasing in the current years base on statistic (Croft, 2016).  The increasing number of teen suicide have cause awareness and brought attention to observance in teen suicide (Croft, 2016). It is said to be the third leading causeRead MoreCauses Of Youth Suicide1316 Words   |  6 PagesYouth Suicide Suicide can be described as a process which includes thoughts of death (killing one’s self), to the actual act of carrying out the suicide attempt. In the United States, suicide is the third leading cause of death among our young people (McWhirter, McWhirter, McWhirter, McWhirter, 2017). Approximately 16% of youth have thoughts of suicide, 13% will attempt to develop a plan, and 8% will actually carry out this plan every year (McWhirter et al, 2017). Every day, five young peopleRead MoreThe Effects Of Depression On Children And Adolescents Essay998 Words   |  4 Pagesdepression occurs in adulthood and that children and adolescents do not experience episodes of depression. The ailment of adulthood and depression is something that is not accurately especially given the current reality in face in society. According to the National Institute of Mental Health, in 2015, an estimated 3 million adolescents aged 12 to 17 in the United States had at least one major depressive epi sode in the past year. Not to solely focus on adolescents, the evidence about children are also alarmingRead MoreTeen Suicide Is The Third Leading Cause Death For High School Students1396 Words   |  6 PagesOver the years teen suicide has increased tremendously. 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I Know Why the Caged Bird Sings Free Essays

Lee 1 Nadia Lee English 2 Mr. List 19 January 2013 I Know Why the Caged Bird Sings By: Maya Angelou 1. Before I chose this poem, I was thinking about choosing a couple of other ones when I finally realized that this poem caught my eye the most. We will write a custom essay sample on I Know Why the Caged Bird Sings or any similar topic only for you Order Now I Know Why the Caged Bird Sings helped me realize the benefits and consequences from both sides in life. I found this poem in Google under the category that said â€Å"poems that talk about life†. If you read this poem and take it literally, than it will mean nothing, but if you take it to the next level by comparing it to life, than it will mean so much more. . The author of this poem is Maya Angelou who is a famous well known poet throughout the world. Angelou is an African American who went through so much pain during her youth years. Angelou was just a child when African Americans were being discriminated by whites. When she was eight years old, her mother’s boyfriend, Freeman, raped and sexually abused Angelou. She then told her brother who later took Freeman to court finding him guilty. After he was released from jail, one of Angelou’s uncles murdered Freeman later turning Angelou into a mute. Angelou stayed mute for five years, but within those years was when she developed a passion for books and literature. Throughout the years, Angelou has written many poems such as On the Pulse of Morning and Just Give Me a Cool Drink of Water ‘Fore I Diiie. 3. I Know Why the Caged Bird Sings was chosen as the title of this poem because it talks about how people in life struggle through so many things and that we must hold on to hope in order to keep moving on in life. Angelou put this as the title because it represents who she is and Lee 2 what she went through. She knows why the caged bird sings because she is the caged bird. The title tells us that this poem is going to talk about what Angelou felt and her experiences of her youth. The caged bird and Angelou have so many things in common. Both have been restricted and need to be let free. This title does reflect the overall theme of this poem. It actually explains so much more of the theme rather than the poem itself. I don’t believe that this poem needs an alternative title. It tells the reader everything already. It already touched my heart and I believe that it’s the perfect title. . I would say that this poem would be a lyrical type of poem. This poem expresses a lot of feelings and emotions that allows the reader to understand what the poet felt. This poem expresses the feelings of being alone, locked up and wanting to be free. I believe that the speaker of this poem is someone who is like a bystander. This bystander is observing one bird that is caged and another that i s free. The situation is that the caged bird is trying to be like the free bird by spreading out its wings, but can’t because of its oppressor making it impossible for him to fly. 5. This poem is written in free verse meaning that it contains no definite meter or a pattern of the rhyme scheme. It is divided into six stanzas containing four to eight lines within each stanza. Each line does not contain a lot of words and the poet makes it short and simple. 6. â€Å"The free bird leaps / on the back of the wind / and floats downstream / till the current ends / and dips his wings / in the orange sun rays / and dares to claim the sky. † This is an example of imagery where Angelou allows us to imagine a bird flying in the sky. The poet did not include any sounds devices in this poem. This poem contains many personifications and metaphors such as â€Å"But a caged bird stands on the grave of dreams† (metaphor). Angelou uses the caged bird and the free bird as an analogy that talks about her life. 7. This poem talks about two birds, one that is free and another that is locked up. Angelou talks about how the free bird is independent and does whatever it wants while the caged bird just Lee 3 hops around in his cage singing. She is comparing the lives of these two birds. The theme is about Angelou’s struggle to survive and how she grew up in a cruel world. The first stanza talks about how the free bird flies endlessly in the sky and floats down a stream relaxing. This stanza is telling us how there are people in this world who are not afraid of anything and can do whatever they please. To them, there is nothing that is troubling them and life is perfect. The second and third stanza then switches over to the caged bird and talks about how he does not have enough space to walk around. The only thing this bird can do is to sing about his rage. These stanzas tell us that there are those like Angelou who don’t possess what others have and uses the only thing they have. The only thing that they possess is hope and without hope there is nothing at all. The fourth stanza talk about how the free bird is provided with everything it needs. If you compare this to life than it tells us how there are others who are spoiled and well cared for. The fifth stanza talks about how the caged bird only has his voice because everything he used to have are now gone. Even though some people don’t have what they need, they still make the best of what they have left. The last and final stanza repeats the third stanza. All we can do is to dream and wish for what we want while living life the best we can. How to cite I Know Why the Caged Bird Sings, Papers I Know Why the Caged Bird Sings Free Essays Reading is an ongoing theme through Maya’s childhood and books even become her lifeline after Mr. Freeman rapes her. They give her an escape from her immediate world as well as the opportunity to find poetry. We will write a custom essay sample on I Know Why the Caged Bird Sings or any similar topic only for you Order Now It is not until Mrs. Bertha Flowers reads aloud to her that she recognizes beauty in the sound of the words and she is shown the aesthetic pleasure available. This offsets the abuse she has suffered and gives her the opportunity to engage with the world once more. It could be argued that, in turn, Angelou’s volumes of autobiographies also offer a form of inspiration that challenges the dominant ideology of racism. Through her written words, she invites one to question the de-humanizing effects of racism and encourages a move from passivity to activism. Racism As Angelou recounts memories of her childhood in Stamps, she manages to maintain a double-edged view of the South. Although she is careful to let the readers know of humorous occurrences, she balances this throughout with reminders of how entrenched racism de-humanizes and terrifies those who are regarded as being at the bottom of the hierarchy. She describes the complete segregation of the town and how African-Americans have been taught to dread the ‘whitefolks’ and is trained by Momma to never be insolent (because of the fear of retribution). I Know Why a Caged Bird Sings stands as a testament to the bravery of those who have been oppressed but not silenced by this deeply racist society. As the eponymous caged bird, that is taught the necessity of living a restricted life through fear, Angelou’s work shows a refusal to be silenced. Sense of Belonging In this memoir, Angelou refers vividly to instances when she feels as though she has been on the outside looking in and it is not until she lives in San Francisco and later lives as a homeless person that she finds acceptance. Before these times, it is as though she is an exile in her family and neighborhood. In the Prologue, she relates to the truth in the poem, that she has not come to stay and experiences this same emotion in St Louis when she first returns to Mother. In San Francisco, she thrives in the newly burgeoning African-American community and as one of many underage homeless persons in the disused car lot she finds the acceptance of her peers that she has been craving. I Know Why the Caged Bird Sings: Top Ten Quotes 1. Wouldn’t they be surprised when one day I woke out of my black ugly dream, and my real hair, which was long and blonde, would take the place of the kinky mass that Momma wouldn’t let me straighten? p. 4 Maya’s self-loathing is revealed here as she describes her idea of beauty. It is as though she has internalized the racist views that see Aryan-white characteristics as the ideal. 2. It was when the owners of cotton fields dropped the payment of ten cents for a pound of cotton to eight, seven and finally five that the Negro community realized that the Depression, at least, did not discriminate. p. 49 This reference describes the slow yet powerful impact of the Depression on the African-American communities in the South in the 1930s. 3. I could feel the evilness flowing through my body and waiting, pent up, to rush off my tongue if I tried to open my mouth. I clamped my teeth shut, I’d hold it in. If it escaped, wouldn’t it flood the world and all the innocent people? p. 84 Maya experiences guilt at this juncture for the death of Mr Freeman. She connects her lie in court (when she said he did not touch her before the rape) with his murder and decides at this point to stop speaking. She believes her words are somehow to blame and decides shortly after to stop talking. 4. Every person I knew had a hellish horror of being ‘called out of his name’. It was a dangerous practice to call a Negro anything that could be loosely construed as insulting because of the centuries of their having been called niggers, jigs, dinges, blackbirds, crows, boots and spooks. p. 105 This quotation comes when Maya works for a white woman (Mrs Viola Cullinan), who decides to call her ‘Mary’ instead of ‘Margaret’. 5. The Black woman in the South who raises sons, grandsons and nephews had her heartstrings tied to a hanging noose. Any break from routine may herald for them unbearable news. For this reason, Southern Blacks until the present generation could be counted among America’s arch conservatives.  p. 110 Here, Maya captures the anxiety of Momma as she waits for Bailey to come home. He is later than expected and her fear for his safety is explained in relation to the dreaded possibility that he may have been lynched. 6. All the Negroes had to do generally, and those at the revival especially, was bear up under this life of toils and cares, because a blessed home awaited them in the far-off bye and bye. p. 125 In this reference, Maya uses a strong measure of irony to challenge the tenet that the meek shall inherit the earth. By questioning this, she undermines both racism and passivity to racism. 7. It was our people falling. It was another lynching, yet another Black man hanging on a tree. One more woman ambushed and raped. A Black boy whipped and maimed. It was hounds on the trail of a man running through slimy swamps. It was a white woman slapping her maid for being forgetful. p. 131 This comes when Maya, her family and neighbors (from near and far) crowd into the Store to listen to the radio broadcast of Joe Louis boxing. The quotation captures the political and social significance of why he must not be beaten. 8. The white kids were going to have a chance to become Galileos and Madame Curies and Edisons and Gaugins, and our boys (the girls weren’t even in on it) would try to be Jesse Owenses and Joe Louises. p. 174 At the much anticipated graduation, Maya is disappointed with the white visiting speaker (Donleavy) for exposing the schoolchildren to the limits of their opportunities. This is, of course, also a critique of the wider society that has encouraged the segregation of school children and the separate but not equal treatment of African-Americans. 9. The needs of a society determine its ethics, and in the Black American ghettos the hero is that man who is offered only the crumbs from his country’s table but by ingenuity and courage is able to take for himself a Lucullan feast. p. 218 In this reference, Maya explains the divisive effect of racism and how this influences responses to crime and justice. As she points out, ‘the needs of a society determine its ethics’ and this redefines who the criminals actually are. 10. The incident was a recurring dream, concocted years before by stupid whites and it eternally came back to haunt us all. The secretary and I were like Hamlet and Laertes in the final scene, where, because of harm done by one ancestor to another, we were bound to duel to the death. p. 260 This somewhat poetic description of how Maya struggles to gain work on the street-cars, despite the company’s racist employment policy, is undercut in the next few sentences. After looking into the hard eyes of a white ‘conducterette’ on the way home, she sees ‘the whole charade’ as having everything to do with her ‘being black and the receptionist being white’. Summary Chapter Twenty Four is concerned with Maya’s toothache and we are told there is not enough enamel left on the offending two teeth for Momma to tie string around and yank them out. There are no African-American dentists or doctors in Stamps – the nearest one is 25 miles away – so Momma says she will take her to (white) Dr. Lincoln in town as he owes her a favor. Analysis In Chapter Twenty Four, the impact of segregation and racist ideology in Stamps is referred to in relation to what should be a simple trip to the dentist. Dr Lincoln’s espoused policy (that he will not put his hand in a ‘nigger’s’ mouth) epitomizes the irrational yet deeply-seated racism of their environment. His hypocrisy is all the more difficult to comprehend when we are told that his business had been saved by the loan he took from Momma. The injustices of the town are also thought to be behind the reason for Momma taking Bailey and Maya to California. It is never explained in these terms, but it tallies with the time period, which comes shortly after Bailey witnesses the hatred of the whites towards African-Americans once more. How to cite I Know Why the Caged Bird Sings, Papers