Round-Trip Copper Reactions Lab Report

AP Chemistry 12/13/11 Round-Trip Copper Reactions Lab The purpose of this lab was to evaluate our skills of decanting a supernatant liquid without losing the solid and successful completion of a series of reactions. This was done through five chemical reactions involving copper. In this lab, elemental copper was put through five different chemical reactions in order to convert it into different compounds. By the end of the fifth reaction, the copper was back to its elemental state. In the first reaction, 0. 95 g of pure copper was reacted with 4. 0 mL of concentrated nitric acid under the fume hood. The solution was swirled until all of the copper had dissolved. The balanced equation for this reaction is as follows: Cu (s) + 4HNO3 (aq) a Cu(NO3)2 (aq) + 2NO2 (g) + 2H2O (l) When the nitric acid came into contact with the solid copper, a brown gas was immediately released into the fume hood. This brown gas was nitrogen dioxide as the balanced equation above shows. As the copper dissolved, the solution slowly turned blue because of the copper ions. In the second reaction, distilled water was added to the copper (II) nitrate solution until the beaker was half full. Then, 30 mL of 3. M sodium hydroxide was added to the solution. The balanced equation for this reaction is as follows: Cu(NO3)2 (aq) + 2NaOH (aq) a Cu(OH)2 (s) + 2NaNO3 (aq) When sodium hydroxide was added to the copper (II) nitrate solution, a bright blue gel-like precipitate was formed instantly. This precipitate was copper (II) hydroxide. The precipitate was blue because of the copper ions. In the third reaction, the c opper (II) hydroxide solution was heated above a Bunsen burner. Continual stirring was required to reduce the â€Å"bumping†, or formation of bubbles that release gas very quickly that have the potential to cause injury. The balanced equation for this reaction is as follows: Cu(OH)2 (s) a CuO (s) + H2O (l) When the solution was heated, the bright blue precipitate slowly began to darken, at first by showing flakes of black, then eventually turning completely black. This is due to the copper reacting with oxygen, or oxidizing. The black precipitate was allowed to settle and then the supernatant, the clear liquid that lies above a precipitate, was decanted, or poured carefully off. Then, 200 mL of hot distilled water was added and the precipitate was allowed to settle to repeat the decanting process again. In the fourth reaction, 15 mL of 6. 0 M sulfuric acid was added to the copper (II) oxide while stirring. The balanced equation for this reaction is as follows: CuO (s) + H2SO4 (aq) a CuSO4 (aq) + H2O (l) + SO2 (g) When the sulfuric acid was added to copper (II) oxide, the solution turned blue. This was due to the formation of aqueous copper (II) sulfate, which produced the copper ions to change the color of the solution. In the fifth reaction, 2. 29 g of zinc was added to the copper (II) sulfate solution under the fume hood. The balanced equation for this reaction is written as followed: Zn (s) + CuSO4 (aq) a ZnSO4 (aq) + Cu (s) When the zinc was added to the copper (II) sulfate solution, the solution started to bubble. As the solution was stirred, it turned a cloudy blue. Small flecks of a brown solid were visible. As the solution became colorless, the brown solid settled to the bottom of the beaker. The solid formed was copper in its elemental state. The color faded from the solution as the copper ions slowly formed into solid copper. The copper was poured into a funnel with filter paper and washed three times with 25 mL of distilled water and ethanol. In order to dry the copper, it was placed on a watch glass weighing 29. 91 g over a beaker half full of water on a hot plate. One the copper appeared to be dry, the beaker was removed from the hot plate and allowed to cool. The copper was massed on the watch glass and was recorded as 30. 79 g. This was left to sit overnight and was massed again the next and recorded as 30. 77 g. By subtracting the mass of the watch glass from the final mass of the copper and watch glass, the mass of the copper was obtained and recorded as 0. 86 g. In conclusion, the percent yield of copper from the original copper was calculated to be 90. % by the formula: actual x 100 = percent yield theoretical 0. 86 g x 100 = 90. 5% 0. 95 g In theory, the amount of copper at the end of the lab should have been the same amount that was started out with. Due to decanting and changing containers, some of the mass was lost. The calculated percent yield above is fairly accurate considering that some of the mass was los t during decanting and transferring the copper from the filter paper onto the watch glass.

Philippine Science Centrum Essay

Student participants learned science concepts from the exhibits and one minute of interaction appeared to have a fruitful learning outcome. Teachers recognized that the exhibits would be useful to their teaching after trying out the exhibits themselves and were certain the visit would help students in their academic advancement. Learning in an informal context through the exhibits can occur and that visits to the PSC are useful. For more than 2 decades, the Philippine Science Centrum presently located in Marikina City has never ceased in offering new features and exhibits year after year. With its internal capacity in interactive exhibit development and fabrication, the PSC has the luxury of producing customized exhibits with locally-sourced materials. Having a ‘hair-raising’ experience with the Van de Graaff exhibit, mimicking the ‘Matrix Move’ at the Wonder House, making an illusion of floating in the air at the Anti-Gravity Mirror, experiencing ‘airlessness’ of the outer space at the Human Gyro, etc†¦are some of the amazing ‘moves’ one will experience at the Science Centrum. To the more than 3 million visitors composed mostly of students and teachers who were engaged and got interested in science through PSC’s exhibits, their experience leaves an indelible mark in their psyche. Post-visit comments, blogs and even press releases attest to the visitors’ educational and entertaining experience at the Science Centrum. How about the other millions of students, teachers and people in all walks of life in the countryside, in the provinces and towns, will they be able to experience the amazing science exhibits in their locality? The Philippine Science Centrum made sure they be given opportunity to be ‘edu-tained’ by the hands-on science modules. As early as 1995, the PSC mobilized its first mobile exhibition, the Adventures in Discovery – Traveling Science Centrum (AIDTSC) to bridge the gap of distance and bring the Science Centrum to the regions. The maiden exhibition in Lapulapu City, Mactan Island, Cebu Province was a blockbuster wherein the AID-TSC no longer found its way back to Metro Manila – it was bought by the City Mayor to be permanently installed in the city and became the centerpiece of the Lapulapu City Center for Excellence. The PSC replicated the 40 science modules of AID-TSC and continued to visit other towns and provincial capitals. Due to unrelenting requests and clamor for month-long exhibitions from various entities in the provinces, the 2nd set, â€Å"Sci-Fun Caravan† was produced and mobilized in 2002. After the successful exhibitions of the 2 mobile exhibitions (from 2002 to 2006) and the assessment that the PSC beneficiaries are larger in numbers at the regions, the PFST Board of Trustees decided to redirect PFST and PSC’s resources to assemble and produce 7 sets of mobile exhibitions starting in 2007. It is also targeted to mobilize 9 traveling sets by 2016 wherein 3 sets will be assigned to each of the three major island-groups of the country: 3 in Luzon, 3 in Visayas and 3 in Mindanao. At the moment, the PSC is right on schedule wherein the 3rd set: â€Å"Science on the Move† was mobilized in 2007, the 4th set: â€Å"Science Works! in 2009, and the 5th set, â€Å"Science Sparks!† was completed and mobilized last year. For the 3rd set, the packaging design of â€Å"pack and go† was introduced wherein the main exhibit is boxed to keep it safe when in transit and its cover when inverted serves as the exhibit stand/platform when in ‘exhibit mode’. The 5th set, aptly known as â€Å"Science Sparks!† deals on energy, electricity and the environment. The 6th PSC mobile exhibition which focuses on Electronics and Communications is now on the initial phase of research and development. It is targeted to be completed by the 2nd quarter of 2014. As the number of PSC’s traveling sets increase, the number of students and teachers ‘touched by the amazing and exciting world of science’ also increases. With 5 sets, the average annual attendance is already at 500,000 visitors. This justifies PFST and PSC’s thrust of exposing and creating interest in science to more students at a ‘faster pace’. From Abra to Samar to Siargao Island and to Lanao del Norte, the mobile exhibitions have already visited 150 towns, provincial cities and capitals with a combined attendance of more than 3.1 million visitors. By 2016, this number is targeted to reach 6 million. Producing the 9 sets of traveling exhibitions is PFST’s top priority but keeping the Science Centrum constantly upgraded with new and exciting interactive exhibits is still a ‘must-do’. The Philippine Foundation for Science and Technology (PFST), a non-profit private organization, manages and operates the Philippine Science Centrum and its traveling exhibitions. PFST is recognized by the Department of Education as a vital partner â€Å"in promoting and developing scientific and analytical thinking among students and promoting quality science education. On the other hand, the Department of Science and Technology recognized the impact of the Philippine Science Centrum by directing its regional offices to install its own Regional Science Centrums. DOST accorded PFST the â€Å"Outstanding S&T Foundation Award† in 1996 and the GAWAD LIDER Award for Exemplary Leadership – Institution Category in 2007. The Philippine Science Centrum received from the Association of Science and Technology Centers based in USA the 2011 Roy L. Shaper Leading Edge Award for PSC’s rapid response and recovery during typhoon Ondoy and as an Outstanding Science Center outside of the United States of America.

Where the experience of male and female slaves similar or different in Essay

Where the experience of male and female slaves similar or different in the nineteenth-century, South - Essay Example were engaged both in urban areas and in the plantations especially in the South which was an agrarian economy and lived and worked under poor conditions. They were also harshly treated by their masters and women subjected to sexual exploitation. However, the experiences of slaves depended on the region, their masters and overseers. In this essay, I will argue that male and female slaves had different experiences in the nineteenth century, south although some aspects were similar depending on the size of the plantation. The antebellum south was a slave society as it had a high population of slaves and depended on them economically, socially and politically and also allowed masters extensive power over slaves unchecked by law.2 In small plantations, men and women performed similar tasks in the fields but in large plantations, men did different work from women. In the Narrative of the Life of Frederick Douglass, Douglass gives an account of the experiences men went through in large plantations having been born into slavery by a colored women and a white father. According to Douglass, women were not given tasks outside the plantation hence these were performed by men and included such tasks as: manning vessels; gardening; driving carriages comprising of horses and coaches; carpentry; chopping wood and using field hand oxen to carry the load home; ploughing and wheat fanning among other field duties.3 Men were also used to transport crops and supplies and also hired out as artisans and craftsmen. Women on the other hand, did household chores such as cooking and caring after the master’s white children. They also did laundry, sewing, milking, and spinning, knitting, and working in rice, tobacco and cotton fields. The role of women was clearly highlighted by Deborah Gray White in her book Ar’n’t I a Woman? She argues that women had a very distinct role from that of men in that they bore children.4 These children whether from a white man (mulatto) or black man

Drug Testing and Employee Drug Use Research Paper

Drug Testing and Employee Drug Use - Research Paper Example It is true that the use of drug is private and that only in some unusual situation can the employers inquire such use from their employees. However, the employers have the right to know of, use of drugs if their employees are involved in illegal drugs. Unlawful use of drugs is data that are not legally private and organizations have the right to identify about such use. This is true because use of illegal drugs can result to incompetence amongst employees. Also, such use of drugs can result to unnecessary accidents amongst employees, the staff, and customers. Further, the employee can compromise beneficial trade secrets of the company or gather individual data about staffs and customers to sell illegally (Frone, 2013). It is the duty/role of employers to provide safe working conditions by postulating drug free environment policies. On the other hand, use of drug is data that are legally private and employers have no right to inquire where about such use from their employees. This is factual in the situation of legal or prescribed drugs employees might be taking (Frone, 2013). For instance, employers are not allowed to inquire employee’s use of such drugs as, cigarettes/tobacco, caffeine, and prescribed medication, unless such use of these substances hinders with the employee’s safety or incompetence. A good example is when an employee is using prescribed drugs to stay competence at a level that allows him/her to perform his/her duty. This is what all employers are allowed to focus on. Employers are not entailed to obtain a list of employee’s prescribed drugs for pre-employment drug test. Healthcare providers responsible for collecting drug samples do not need to inquire for the list either. As a manager of a certain company, one should make sure that he/she has implemented drug policies and rules that should be adhered to by all staffs. Some of the policies should include, the company having a neutral third party medical depiction to analyze

Critical appraisal two research studies Essay Example | Topics and Well Written Essays - 3000 words

Critical appraisal two research studies - Essay Example The second article, Simon John Palfrey man tends to get on the psychological state of the patients, trying to clinically establishing the expectations and reasons for patients, seeking the treatment. Thus these are two papers are from the same field, though of different tradition and aim. The first paper is essentially based on quantitative research where the paradigms or testing ground would be parameters like reliability and validity while the second one is a qualitative research that would need analysis of different parameters like the researcher’s reflexity, the context in which the research took place, selection of research participants, etc. This essay critically evaluates the paper in terms of research design and their potential contribution towards effective practice, encompassing the concerned ethical and political issues. The agenda is to travel further down the concept and try to establish the barriers for implementing research in the workplace and the effective means of overcoming it. Thus to effectively analyze the research paper it becomes important to understand the background of the condition described, followed by abstract of the papers to be reviewed and their critical analysis. Varicose veins are enlarged veins that appears swollen and elevated above the skin surface. They are distinctly visible not just because of their twisted and bulging look but also their color wich can be dark purple or blue. Usually found on the backs of the calves or inside of the legs, the valves in the veins permitting the blood flow towards the heart stops functioning properly. This leads to development of blood pools in the veins causing them to dilate.Around 1 out of 2 people over the age of 50 suffer from varicose veins and is more commonly observed in women than men. Hemorrhoids or commonly known as piles are also a type of varicose vein. Proper exercise, losing obesity, elevating the legs while resting and not crossing legs while

Nancy Morejon Essay Example | Topics and Well Written Essays - 1250 words

Nancy Morejon - Essay Example There she absorbed and assimilated Afro-Cuban culture until she identified herself with the very essence of her beloved Havana" (Cordones-Cook 2003:33). Cordones-Cook (2003) asserts that Morejon in her poetry projects "a clearly matrilineal consciousness that establishes connection and filiation," a kind of sympathetic female bonding, with legendary female ancestors. Gonzalez (2005) would understand this as Morejn's poems referring to Yoruba deities, known as orishas, and honoring the "living dead," the eggun or ancestors. She said Morejon dominates these poetic spaces with words of wisdom from both the African ancestors and the orishas, who exercise their eternal influence. A study of her poems suggests that Morejn is obsessed with her past, and often uses poetry as a way of exploring it. It is in those poems that she revisits Africa, encounters the grandparents she never met, and experiences the hardships of slavery. As a result, she often gives voice to people who don't normally have one. Morejn is a strong believer that ancestors and loved ones who have passed on, continue to affect people's daily lives. Honoring the living dead or the ancestors may be seen from the perspective of communicating with them because of "Frustrations in personal life" as Xianglong (2007) would see it. Xianglong (2007) looked into filial consciousness into the thinking that intersects the past and future. Accordingly, frustrations in personal life are one occasion for a person to bridge the time and reach out to the dead. Indeed, in Morejon's culture, the spirits of ancestors are spiritual guides (Gonzalez-Wippler 1998:76). After death, spirits are said to remain around their relatives here on earth, for protection and guidance. Invoked in every religious ritual, they often participate in family decisions, giving their approval or disapproval in family affairs. Morejn's poem, "In Front of a Mirror," refers to the importance of "our dead ones" and how present they are in their daily lives If the parks blossom overflowing with fresh tulips then the boulevard brings in the scents of your loved ones, and, above all, of your dead ones. (Morejn in Looking Within 109) Morejon is conscious that the dead are ever with them - participating in their present conditions. Maier (2005) asserts that one poem closely identified with Morejon is "Persona." This poem, according to David Frye (2000), is a relatively recent one (1999), but it is also an update of the earlier "Mujer negra" ("Black Woman"). In "Mujer Negra" ("Black Woman)" she moves through various generations discussing immigration, slavery, poverty, rebellion and the independence movement (from Spain), and finally, affirmation of the Afro-Cuban as a human being after 1959. According to Maier (2005), this poem emphasizes the slave's point of view, and demonstrates the influence of ideological freedom found in the Cuban Revolution. She underscores the racial together with the feminist dimensions of Cuban nationalism by making the Black woman the central figure and the protagonist of the contemporary era "Black Woman," and "Persona," exemplifies well the characteristics for which Morejon and her work are known and admired. These traits include a strong identification with her family, with the

The marriage cure, inadequate solution of poverty Essay

The marriage cure, inadequate solution of poverty - Essay Example From ancient times a marriage supposed to be the effective tool to eliminate poverty. But is it an adequate solution today Literary critics express different views as for the Boo's article message. Some of them suppose that the research suggesting that governments and individuals tend to benefit from an increase in marriage rates is at this point very persuasive, and don't see much point in being coy about it. Marriage is probably the most cost-efficient antipoverty instrument a society possesses (Stewart, 2004). The author gives special detailed attention to the difficulty which can follow single women in marriage rush. The article describes the problems of two single women and the imperfection of the institution marriage at the beginning of the 21st century. In the article Boo describes the realities of a marriage promotion program and their outcomes for low-income woman. She wrote: "Still, the days now contained enough hours for a reasonable woman to fret about her future" (Boo, 2003). In one of her interview Boo argues that: "And if, inspired by that indoctrination, Kim, whose income was less than ten thousand dollars, manages to meet and marry a man who makes ten thousand dollars, their combined income would remove both of them... Boo criticizes the Bush's welfare reform to eliminate poverty by marriage and sees it as inadequate solution giving supported reasons. Some critics argue that success in the workforce may make women more independent and therefore more selective about the men they will consider marrying. In addition, more time at work means less time to pursue relationships, especially for single mothers whose time is already stretched thin (Stewart, 2004).. The important fact to note is that poverty is a complex problem which is difficult to solve in one day. Bear in mind the facts mentioned by Katherine Boo it is possible to say that if this problem of poverty can be solved by successful marriage, our society would not have poor creatures looking for better days. Race, gender, familial status, age, and place of residence are some but not all of the characteristics that enhance the risk of living in poverty. Boo gives a vivid examples contrasting with those "rosy dreams" proposed by Bush's administration. She describes that Kim's annual income was: "five thousand dollars, but, except for ten months when she and her husband first separated, she had not received welfare. The child support was supposed to have covered us, but when it stopped coming I couldn't afford a lawyer" (Boo, 2003). The marriage cure is nothing more than survival of time affected the mind of many single women. "Marriage promotion programs, therefore, must be viewed in the context of battered women's lives and how poverty and children affect their decision-making. Most moms I know will do anything for their children and this often includes putting up with years of violence and abuse. When you tell a woman who is desperately trying to keep a roof over her head, put food on