Determination of % Composition of Pennies Using Redox and Double Displacement (Precipitation) Reactions Essay Example for Free

Determination of % Composition of Pennies Using Redox and Double Displacement (Precipitation) Reactions Essay Introduction: Oxidation involves the gain of electrons of hydrogen or the loss of oxygen or decrease in oxidation state. If zinc completely reacts with HCL, then the theoretical yield of copper should be equivalent to the actual yield. Purpose: In this lab, we will determine the percent composition of a modern (post-1982) penny by using a strong acid to react and dissolve the zinc core, leaving only the copper coating. Once only copper remains, we will compare its mass to the entire mass of the penny to determine how much of a penny is copper and how much is zinc. 1. Obtain one 50.0 mL beaker, and label the beaker with your NAME and HOUR. 2. Obtain a penny dated 1982 or later. Wash the penny with soap and water to get it clean. 3. Using a triangular file to make FOUR oppositely-placed small grooves into the edge of the penny (the marks with be approximately 90 degrees apart. The grooves must be deep enough so that the zinc is exposed, but not so deep that the pennys mass is greatly affected. 4. Clean the top and bottom surface of the penny with steel wool until it’s shiny. Rinse the penny in acetone and dry it on paper towel. 5. Determine the mass of the penny on the balance, and record the mass in the table on the bottom of the page. Removed the penny from the balance using tweezers and place it in its beaker. 6. While wearing gloves, carefully pour 50 mL 3M HCl into the beaker. 7. Place your labeled beaker under the fume hood to react. Observe the effect the acid has on the copper outside of the penny. Questions to answer to help guide the development of procedures for the determination of the percent copper and zinc in pennies through titration and gravimetric techniques: 1. What is the weight of a post 1982 penny? 2.5 grams 2. What is the percent copper and zinc in a post 1982 penny? 97.5% zinc, 2.5% copper 3. How many grams of copper and zinc are in a post 1982 penny? 97.5 grams zinc, 2.5 grams copper 4. How many moles of copper and zinc are in post 1982 pennies? 5. Write a balanced reaction of zinc with HCl. Zn(s) + 2HCl(aq) ZnCl2(aq) + H2(g). 6. How many moles of HCl are needed to react completely with all of the zinc in a post 1982 penny? 2.5 7. In a procedure developed to determine the percent zinc in post 1982 pennies, 50 ml of an HCl solution was used to react (dissolve) all of the zinc in the penny. To ensure complete reaction, the solution contains twice as many moles of HCl that is actually needed. What concentration of HCl should be used? In the scenario described in problem 7, what is the amount (in moles) of excess (unreacted) HCl in solution? 9. How many moles of NaOH would be needed to completely react with all of the excess HCl determined in problem 8? 10. As described in problem 7, a procedure was developed to determine the percent zinc in post 1982 pennies. In that procedure 50 ml of an HCl was used to react (dissolve) all of the zinc in the penny. To ensure complete reaction, the solution contains twice as many moles of HCl that is actually needed. To determine the percent zinc in the penny, the excess (unreacted) HCl was titrated with NaOH. Determine the concentration of NaOH needed if you want to use approximately 25 mL of NaOH to titrate the excess HCl. 11. Write the balanced chemical reaction of zinc with HCl (same as problem 5). Is the product of this reaction soluble in aqueous solution? 12. Write the balanced chemical reaction of the product of the reaction described above (problem 11) with NaOH. Is the product of this reaction soluble in aqueous solution?

Kirtrines Basement :: Personal Narrative, Autobiographical Essay

Kirtrine's Basement "Sister Lopez?" I looked down the winding staircase into the murky depths of my neighbor's unfinished basement. "Sister Lopez, can I talk to you?" The only sound was the steady hum of the sewing machine, so I quietly took the stairs two at a time. I was twelve years old--polite and refined, but not overly patient. My mother, a wonderful but slightly overzealous Mormon Relief Society president, had sent me with a Homemaking invitation to give to the ever-elusive, inactive Sister Lopez. Sister Lopez was sitting at a large table, feeding canvas into a huge sewing machine. The only light in the room was the leftover sun that managed to squeeze through the window well. It illuminated her hair which fell to her shoulders like blackberry satin. I watched her look up at me with only mild curiosity. "Hello." "Hello... I wanted to give you this." "Thanks. Why don't you sit down?" Her face was so flawless, so unreal. She looked like a woman in one of my mother's catalogues--Lands End, maybe, or J Crew. I took a folding chair from its resting place on a cement wall. "How are you, Sister Lopez?" I asked. It was all I had ever been taught to ask an adult. Sister Lopez laughed the most sincere laugh I had ever heard. I suppose it was the laugh of a jubilant woman, but at the time I wasn't familiar enough with laughter to tell. "Call me Kirtrine." "Kirtrine." I liked the way the word sounded on my lips. "And the real question is," she continued, "how are you?" To say the least I was startled. "Me? I'm fine." As if anyone needed to ask how I was; it was perfectly apparent to any semi-competent onlooker. I was almost thirteen, with matted brown hair, awkward, angular glasses, and an uncomfortable weight gain where hips should have been. A pubescent nightmare, I had acne like the "before" picture on a skin care infomercial and crooked teeth, surely the envy of every jack o' lantern. How was I? I was a mess. "Tell me about school," she prodded, though it sounded like anything but prodding."Any cute guys?" I sat there, on a cold, hard folding chair, surrounded by bolts of colorful cloth. I opened up like I never had before in that room: I cried with the ice blue chiffon, I laughed with the tomato red flannel. I was as pristine as crisp white linen; I was as sophisticated as black velvet.

Cybercrime in Today’s World Essay

I have been asked to write a paper concerning cybercrime in the world today. I will go over what cybercrime is, how much it is affecting the United States, possible ways of enforcement and why or why not enforcement would be effective. What is a cybercrime, in your own words? Cybercrime is using computers or technology in order to steal information or to create fake identities over the World Wide Web. It is a growing problem in the world today, especially in countries like China, Japan and the United States where populations are high. Phone scams are another type of cybercrime as people will try to glean vital information from another by pretending to be a grandchild or a salesman. Cyberspace allows people to invade another person’s or company’s computer and download sensitive materials such as social security numbers, birth certificates and tax information. What is the extent of cybercrime in the United States? Computerescape. om says that â€Å"Cybercrime is widespread throughout the United States with 73% of American internet users being victims of cybercrime, either through viruses, online credit card or identity theft†*. With over 300 million Americans in the US, that comes out to 219 million Americans that have been or are currently victims of a cybercriminal. Most of the victims of identity theft are infants and the elderly. My own infant cousin had his social security number stolen shortly after his death. It took several months to recover it. How do you think we should control / enforce cybercrime? I personally believe that the only way to control cybercrime is to attach a major virus to sensitive files, so that when an unauthorized person tries to access it, it attaches itself to that person’s computer, downloads any information regarding the owner of the computer, sends that information to the authorities, and finally scrambles all data on the computer. The authorities will then be able to make an arrest and unscramble the computer so that evidence can be obtained. The offender should then have an appendage cut from their body on national television, so that others thinking of committing the same crime will hopefully be deterred. If the person should offend again, then they should be stoned until dead by the people that they have stolen from. Do you think enforcement can be effective? Why or why not? I don’t think that any type of enforcement would be effective as tracking anything in cyberspace is time consuming and if the person was determined enough, they would find a way around the enforcement. Security cameras are an excellent point. You can have the main points of a store being watched by cameras, but the only places you have issues with theft is in the cameras blind spots. A security system will alert you if someone comes in through a door or window, but isn’t programmed to respond if a person decides to cut a hole in the wall or ceiling and enter the premises without ever tripping the system. If someone wanted to commit a robbery and they knew that a police patrol car passed by every 45 minutes, they would wait until 10 minutes after the patrol car had passed and then rob the business, knowing that it would be at least another 10 minutes before police could respond. Criminals will always find a way to circumvent the enforcers of the law.

Effect Of Tourism On Asian Economic Growth - Free Essay Example

Sample details Pages: 6 Words: 1912 Downloads: 6 Date added: 2017/06/26 Category Statistics Essay Did you like this example? 1.1 Introduction Tourism is one of key industry in the development of some countries in Asia. Malaysia, itself depend on tourism in its nation growth. In Asia, country like Malaysia has benefited a lot from the development of its tourism industry. The developments of tourism in Asia are differing amongst countries. Natural disaster such as air pollution, floods and earthquake will bring an effect on the tourism industry in Asia. 1.2 Environmental Disaster and Tourism There has been previous research regarding to tourism which study the relationship between natural disaster and tourism. In the year of 2010, hazardous flooding in Pakistan has influence its economy growth. Decision-making by tourists on travel plan is influenced by economic, technological, international or political, sociocultural and environmental factors including those directly related to environmental and natural hazards ( Mathieson and Wall, 1993). According to Sinclair and Stabler (1997), the range of goods and services encompassing tourism include natural resources and especially the non-price feature and the positive benefits derived from attractive environment and the negative effect of pollution. Sinclair and Stabler noted that the perceived cost of travel increases by the realization of natural disaster has effect tourism at all. Don’t waste time! Our writers will create an original "Effect Of Tourism On Asian Economic Growth" essay for you Create order The research by Campos, (1999) stated that there was relationship between tropical cyclone (natural disaster) and the income of hotels (tourism industry), meanwhile Chang (1983) found that hurricane and other natural disaster can decreases revenues to a municipality through reduce tourism revenues, although the increases assistant by Federal Government to the effect area. 1.3 Tourism in Asia: Development of Tourism in Some Countries in Asia Comparison and effect of tourism in Asia on the development of economy can be discussed specifically by making comparison between the chosen countries. The countries included on the list of this study were Malaysia, Singapore, Brunei, Philippines, Indonesia,Thailand, Vietnam, Laos and Cambondia. 1.3.1 Malaysia The research by Mohd Hafiz Hanafiah and Mohd Fauzi Mohd Harun in June 2010 regarding to tourism in Malaysia show that tourism in Malaysia is the third largest industry after oil and automobiles. Malaysian economy will increase due to the increase in tourism sector. Number of tourists visits Malaysia is a major factor which influences the Malaysian economy alone. During Asian Financial Crisis 1997, number of tourists declined and reached a new record after the economic stalemate. There was another research which shows how tourists influence the growth of tourism in some countries. According to Song and Witt (2000), they described tourist products as the amount of tourism demand that the consumers are willing to acquire during a specific period of time and under certain conditions which controlled by the explanatory factors used in the demand equation. Smeral (1988) and Syriopoulos and Sinclair (1993) empirically examined the relationships between the variables underlying the determinants of tourism demand. Lim (1997), Song and Witt (2000) and Song et al. (2003), used econometrics forecasting model to which forecasts changed as a result of changes in the variables that act as economic drivers of tourism. Loeb (1982), Nordstrom (1996), Uysal and Crompton (1982) have used the demand function approach to identify the quantitative relationships of tourism demand. Jorgensen (1996) and Muller (1999) have focus on the statistical properties of an important time serie s, namely on the international tourist demand. 1.3.2 Singapore In Singapore the research analysis on tourism was done by Xianming Meng, Mahinda Siriwardana, Brian Dollery and Stuart Mounter in June 2010 on the impact of the World Financial crisis in 2008 by using CGE analysis. They found that tourism industry is one of the important sectors in Singapore that contribute to the increase in the country economy development. Singapore tourism was greatly effect during the World Financial Crisis in 2008. It shows on Singapore Tourism Board (2009), tourism declined 13.5% in the first half of 2009 compared with the first half of 2008. Blake and Sinclair (2003) used a 98-sector CGE model of the US economy to estimate the impact of 911-event in the absence of any offsetting policy response which is when the fall in the tourism expenditures reduces GDP and it will worsen the government budget and under different policy responses. Blake et al. (2003) use CGE model to analyse the impact of Foot and Mouth decease (FMD) on tourism and the UK economy. From the model it can be consider that there is a fall on the real GDP, declining in exports, increase in BOP deficit and falls in government revenue. 1.3.3 Brunei The research by Kwabena A. Anaman and Chee N. Looi in September 2000 was on Economic impact of haze-related air pollution on the tourism industry in Brunei Darussalam.They found that haze-related air pollution is a major problem why Brunei has a problem on increasing their number of visitors comes to their country. The causes of this problem in Brunei tourism is because of the pollution that happen and country losses about one million to the tourism industry.   The pollution and human health effects tourists to visit Brunei and this will decreased the benefits of Brunei economy. 1.3.4 Philippines In Philippines, study by (October 2000) by P.L. Cadiz and H.P. Calumpong (2000) on the revenues gained from tourism show that Philippines has a potential to increase in the tourism industry especially in Apo Island. According to White and Dobias 1990, the overall cost and benefits of tourism development options showed from a particularly of who is incurring the cost and who is benefiting. They also agree that tourist will visits Philippines because of the beautiful beaches and marine parks. From study of White 1996, the entire island coral reef was declared a marine reserve and a small portion a fish sanctuary in 1986 and this boost the economy growth. 1.3.5 Indonesia Local Economic Impacts of Dragon tourism in Indonesia (2000) by Matthew J. Walpole and Harold J. Goodwin (2000) in their study of Local Economic Impacts of Dragon tourism found that tourism in Indonesia is an important industry to increase Indonesia economy so they can compete with other country. The number of tourists visit Indonesia will be show from the environment of this country. According to Goodwin, Kent, parker and Walpole 1997 and1998, many international tourism emerged rather than industrialize countries. Brohman 1996, believe that tourism industry are increasingly being promoted in rural areas as a means to combat the historic trends of dependency and inequality. From Boo 1992 perspective, ecotourism is increasingly held to embody both sustainable development ideals and conservation. 1.3.6 Thailand The study by Aswin Sangpikul and Ardash Batra (2007) on perpective of Thai Youths regarding to ecotourim found that Thai youths had a general knowledge and experience on ecotourism industry. The study is to decide their knowledge and attitude towards ecotourism as well as to survey their travel experiences relating to ecotourism. From the statement of Walailak University, 1997, they believe that people are regarded as one of the key factors for the success of ecotourism development. The study shows that Thai youths still have a limited knowledge on ecotourism but they understood the meaning of ecotourism.   Thai youths also have a problem to know on how ecotourism can effect on Thailand tourism. Besides, youths on Thailand like to visit places that are maintained and preserved beauty and pureness.From the previous study of Tonekaew, 1998 and Kunarucks, 2000, two concerned parties have been identified to provide more knowledge and promote ecotourism among Thai youths, namely ed ucational institutes and government agencies. 1.3.7 Vietnam Professor Malcolm cooper (1998) makes a research about the roles of IT in the development of tourism. He found that IT playing important roles in developing a national tourism industry based on the sustainable development model.   Vietnam is located in both a tropical and a temperate zone. This is because it is a fastest way to inform others about the tourism industry in Vietnam. The study is to compare the information provided by current systems, and managing development while preserving the value of the cultural and physical environment. Besides, Vietnam contributes on the increase in the countrys GDP. Good environment quality leads country to have more tourists visiting Vietnam. 1.3.8 Laos Steven Schipani (2006) study how tourism benefitted Upland Rubber Cultivation in Laos. In the study, he found that Laos tourism will reach a million of tourists arrive over a year. The study of Laoss tourism estimated that visitors are interested in the countrys natural and cultural attractions.   The study of Laos industry is to examine the ecotourism as an alternative to Upland Rubber cultivation in the Nam Ha National protected Area, Luang Namtha. Ecotourism in Luang Namtha generate financial benefits for local people, providing small group for cultural exchange, minimising adverse cultural and environmental impacts and generating public funds for environmental and cultural protection. Ecotourism activities and rubber plantations can both be conducted independently. 1.3.9 Cambodia Kathryn Conway (2008) whom make a research of ecotourism, poverty, and conservation in Prek Toal found that ecotourism revenues can be analyzed using poor subsistence fishing village on Cambodias Tonle sap lake, the conservation organization Osmose to finance poverty intervention programs and promote conservation in a threatened ecosystem. This study is to examine the local perceptions of tourism. According to Valene Smith, shes defines tourism as a temporary and voluntary travel to à ¢Ã¢â€š ¬Ã‹Å"a place away from home for the purpose of experiencing a change. In Cambodia tourism, the level of general awareness of tourists activities is low in the community wide. Besides there is a limitation on the perceptions of any negative impacts associated with tourism. 1.4 Method and Analysis used by Researcher in The Past Method and the way analysis which has been used by previous researcher are vital in this research and therefore it will bring great advantages in this research especially in chapter 3 which will be discussed later. Mohd Hafiz Hanafiah and Mohd Fauzi Mohd Harun (June 2010) study on Malaysia tourism use Gravity model and economic data to analyse the tourism demand in Malaysia. Xianming Meng, Mahinda Siriwardana, Brian Dollery and Stuart Mounter ( June 2010) study on Singapore tourism use CGE models, data and parameters to estimate the negative effects of the 2008 world Finacial Crisis. Kwabena A. Anaman and Chee N. Looi (Septemver 2000) using OLS regression Model and Linear and log-linear on the visitor and tourist..P.L. Cadiz and H.P. Calumpong (October 2000) study on Philippines tourism used questionnaire to determine the number of tourists visiting Apo Island every month other than monitor the number of visitors diving and snorkelling outside and inside the marine sanctuary. Meanwhile, Matthew J. Walpole and Harold J. Goodwin (2000) study on Indonesia tourism used macroeconomics techniques ,questionnaire and ANOVA test to examine the magnitude and distribution of tourism employment and revenue generation in communities in an Indonesian Park.Aswin Sangpikul and Ardash Batra (2007) study on Thailand tourism used questionnaire and ANOVA test to decide their knowledge and attitude towards ecotourism as well as to survey their travel experiences relating to ecotourism.. Professor Malcolm cooper (1998) study on Vietnam tourism, Steven Schipani (2006) study on Laos tourism use data management and forecasting method. Kathryn Conway (2008) study on Cambodia tourism used fieldwork timeline, translator / assistant, sampling, consent process, data collection and data management  to examine the local perceptions of tourism. 1.5 Conclusion As every of us knew tourism play a big role in the development of economy in some countries. Issue such as natural disaster certainly degrades the growth of tourism in the country and of course economy as well. In this research, the event of how the situation of tourism in some countries in Asia will be used in completing this research successfully. Besides, the method and analysis used by previous researcher will give a big help in this research as it will help the researcher in the formation of questionnaire and other relevant analysis. And this will include how tourist had a strong relationship in the development of tourism economy.