Determination of Ksp of Copper(II) Iodate by E.M.F. Measurement Essay Example for Free

Determination of Ksp of Copper(II) Iodate by E.M.F. Measurement Essay Introduction: Copper(II) iodate(V) ionizes weakly in water: Cu(IO3)2 + aq Cu2+(aq) + 2IO3-(aq) For a saturated solution of copper(II) iodate(V), concentration of IO3- ions doubles that of the Cu2+ (aq) ions, and Ksp of Cu(IO3)2(s) can be calculated by determining the concentration of Cu2+(aq) ion of a saturated Cu(IO3)2(aq). The e.m.f. of a galvanic cell consisting of a Zn(s)/Zn2+(aq) half-cell and another half-cell containing a copper strip in contact with a saturated solution of Cu(IO3)2(aq) is measured by a commercial DMM. Concentration of Cu2+(aq) is determined with reference to the EO values of the Zn(s)/Zn2+(aq) and the Cu(s)/Cu2+(aq) couples as well as the Nernst equation for a metal/metal ion half-cell: where n is the number of electrons transferred in the reduction process. ? Zn Zn2+ + 2e- Cu2+ + 2e- Cu ? n=2 For the Zn(s)/Zn2+(aq) half-cell, = -0.76V For the Cu(s)/Cu2+(aq) half-cell, Ecell = ER EL = {(+0.34) + 0.0295 log [Cu2+(aq)]} {(-0.76)} = (1.10) + 0.0295 log [Cu2+(aq)] When the voltage of the cell system is measured, the concentration of Cu2+ can be determined by the above equation. Therefore, the solubility product can be calculated by the above principle. Purposes: To determine the solubility product of copper(II) iodate(V) at room temperature and pressure by e.m.f. measurement. Apparatus and Reagents Used: Apparatus used: Well-plate; Plastic pipettes; Copper wire electrode; Zinc plate electrode; Digital multimeter (DMM); Connecting wires with crocodile clips; Filter paper strip, and Sand paper à ¯Ã‚ ¿Ã‚ ½1 à ¯Ã‚ ¿Ã‚ ½2 à ¯Ã‚ ¿Ã‚ ½1 à ¯Ã‚ ¿Ã‚ ½1 à ¯Ã‚ ¿Ã‚ ½1 à ¯Ã‚ ¿Ã‚ ½2 à ¯Ã‚ ¿Ã‚ ½1 Reagents used: 1M ZnSO4(aq); 0.3M KIO3(aq); 0.15M CuSO4(aq), and Saturated KNO3(aq) Chemical Reactions Involved: The equation of dissolution of copper(II) iodate(V): Cu(IO3)2(s) + aq Cu2+(aq) + 2IO3-(aq) The equation of redox reaction between Zn and Cu2+: Cu2+(aq) + Zn(s)Zn2+(aq) + Cu(s) Procedures: 1. 50 drops of 1M ZnSO4(aq) were placed into a well of the well-plate; 2. 25 drops of 0.3M KIO3(aq) were placed into an empty well next to the well containing the 1M ZnSO4(aq), by using a clean Jumbo pipette; 3. The plastic pipette used in step(2) was cleaned. By using the same plastic pipette, 25 drops of 0.15M CuSO4(aq) were added and stirred well with a micro-stirrer or toothpick. 5 minutes were waited to attain equilibrium; 4. The two wells were connected by a strip of filter paper moistened with saturated KNO3(aq); 5. A clean homemade copper wire electrode and a clean zinc plate electrode were placed into the well containing the pale blue suspension and the well containing the 1M ZnSO4(aq) respectively; 6. The prepared galvanic cell was connected to a DMM. The steady voltage developed was recorded. Observations: When the galvanic cell completed in step(5) was connected to the DMM, a steady voltage was developed. Data and results: Temperature of the aqueous solution = 26? E.m.f. of the cell formed by Zn(s)/Zn2+(aq, 1M) and Cu(s)/Cu(aq, saturated) = 0.997V Discussions: 1. The expression of the Ksp of copper(II) iodate(V) = [Cu2+(aq)]eqm [IO3-]2eqm 2. By the equation evaluated in the introduction, Ecell = (1.10) + 0.0295 log [Cu2+(aq)] = 0.997V 0.0295 log[Cu2+(aq)] = -0.103 log[Cu2+(aq)] = -3.492 ? [Cu2+(aq)]eqm = 3.225 à ¯Ã‚ ¿Ã‚ ½ 10-3 moldm-3 Concentration of Cu2+(aq) in the saturated pale blue suspension = 3.225 à ¯Ã‚ ¿Ã‚ ½ 10-3 moldm-3 3. By the equation of dissolution of copper(II) iodate(V), Cu(IO3)2(s) + aq Cu2+(aq) + 2IO3-(aq) [Cu2+(aq)] : [IO3-(aq)] = 1 : 2 ?[IO3-(aq)]eqm = 2 à ¯Ã‚ ¿Ã‚ ½ 3.225 à ¯Ã‚ ¿Ã‚ ½ 10-3 = 6.450 à ¯Ã‚ ¿Ã‚ ½ 10-3 moldm-3 Concentration of IO3-(aq) in the saturated pale blue suspension = 6.450 à ¯Ã‚ ¿Ã‚ ½ 10-3 moldm-3 4. The value for Ksp of Cu(IO3)2 = [Cu2+(aq)]eqm [IO3-]2eqm = (3.225 à ¯Ã‚ ¿Ã‚ ½ 10-3) à ¯Ã‚ ¿Ã‚ ½ (6.450 à ¯Ã‚ ¿Ã‚ ½ 10-3)2 = 1.34 à ¯Ã‚ ¿Ã‚ ½ 10-10 mol3dm-9 5. From the data of the Faculty of Chemistry and Technology, University of Split, the literature value of Ksp of Cu(IO3)2 is 6.94 à ¯Ã‚ ¿Ã‚ ½ 10-8 mol3dm-9 [1]. Obviously, the literature value was much larger than the experimental value. The discrepancy came from several reasons: 1 The experimental temperature was 26?, which was different from the expected room temperature 25?. As temperature is the main factor of Ksp, the discrepancy of Ksp was caused by the difference of temperature; 2 The low quality of copper and zinc electrode may affected the e.m.f. taken from the DMM, so the Ksp result was also affected; 3 The concentration of solutions prepared may be different with the expected value. The e.m.f. given out may not equal to the theoretical values, so the Ksp obtained may be different. Conclusion: By the e.m.f. method, the solubility product of copper(II) iodate(V) at room temperature and pressure was determined. Ksp for = 1.34 à ¯Ã‚ ¿Ã‚ ½ 10-10 mol3dm-9 Reference: [1] : Solubility Product Constants, Faculty of Chemistry and Technology, University of Split http://www.ktf-split.hr/periodni/en/abc/kpt.html

Parallels Between The Causes Of The 1929 Wall Street Crash And The Curr

The purpose of this essay is to explore the parallels between the underlying factors which led to the 1929 Wall Street Crash and the present Credit Crunch. The 1929 Wall Street crash was caused by weaknesses in the US economy. After WW1 the USA experienced a decade of economic growth generated by the levels of mass production and industrial growth during the war years. This along with the popular culture of success (the Jazz and party scene) made America appear a hugely prosperous country. However, the glitz and glamour of USA was superficial as very few reaped the benefits of this wealth. There were also many weaknesses to this economic growth as it was not achieved in a wholly sustainable way. This can be compared to the USA of the last decade. The economy has appeared to be healthy and prosperous; however, like the economy of the 1920s, there have been many underlying weaknesses. The Republican party of the 1920s believed in low taxation on businesses and protectionism, marking a clear break with the Wilson ideas of ‘free trade’. They introduced acts such as the 1922 Fordney-McCumber Tariff, which raised import duties on chemical and farming products and the 1925 Revenue Act which abolished gift tax, halved estate tax and cut maximum surtax from 40% to 20%. Both presidents of the 20s, Harding and Coolidge, very much believed in ‘minimal government’, believing that the government’s role was to balance the budget, reduce taxes and reduce debt. This Republican view was the essential basis of the economic prosperity seen during the period. They allowed businesses to operate within a wall of economic protection. Profits were increasing and pushing the economy and the feeling of ’prosperity’ yet due to the lack of government r... ...wnward spiral towards a downturn. In the last decade the same thing has happened in regards to securitization and over lending by banks to individuals. The parallels that can be drawn between the two eras can give us a clearer understanding of our current economic crisis. It can also help economists in coming up with solutions as the eras share vital characteristics. However it is just as important to take into account the differences between the two eras, as it would be a mistake to see the eras as an analogy of one another. US society has changed a lot since the 1920s, and the 1920s certainly never witnessed the levels of consumerism that we witness today. However it is perhaps globalization which makes the crisis we face now more complicated to deal with as this has had one of the most profound effects on markets and worldwide trade over the past seventy years.

Ecotourism in Kenya Essay

Kenya is a landlocked country in the continent of South Africa. It is surrounded by five countries. Kenya is a popular destination for tourists travelling to Africa as it offers tourists camel safaris, trekking, game fishing, white water rafting, ballooning, diving, wind surfing and donkey safaris. The major ecotourist attraction in Africa is one of the 40 national parks in Kenya that offer an insight into the lives of animals and their habitat. Unfortunately, 70% of national parks and game reserves are on pastoral lands, particularly Masai land. Ecotourism is a major contributor to Kenya’s economy. There are 55 000 people employed in the wildlife industry alone. And the wildlife market generates half of the country’s foreign exchange earnings. Therefore, the wildlife market is the biggest contributor to Kenya’s foreign economy. Ecotourism has had both positive and negative impacts on the wildlife environment, people and economy of Kenya. The economy, the livelihood of the people, and the maintenance of the ecosystem have had positive impacts on Kenya. Kenya’s foreign exchange earnings are from tourism and 80% of the tourist market is drawn from wildlife. Also, the Masai herders who inhabit bush land north of Mt Kenya have allocated 8 765 hectares of their land, (which teems with elephants, zebras, giraffes, wild cats) for wildlife conservations. The revenue from tourist lodge tours then go back to the community which is used for children scholarships, maintenance, development and general income. Therefore, the above have had a sustainable impact on tourism. Ecotourism also promotes sustainability of the wildlife. In Kenya, a living elephant is worth around $14 375 for every year of its life whilst the ivory from an elephant is worth about $1000. Each elephants herd earns as much as $610 000 each year. This promotes the maintenance of the elephants, minimises poaching and ensures protection of wildlife as well as livelihood for the people. Another area, the Serengeti Plains, is famous for the migration of wildlife. The national park attracts large numbers of tourists, who are attracted to the large migration of wilder beasts, cats and zebras. This experience encourages travel to the area and highlights an appreciation  for the ecosystem. In all these encounters, education is a characteristic of the various tours. There have also been some negative impacts that have affected the environment, the indigenous population and tourists. Some of these include pollution, habitat destruction, littering and armed banditry. An example of this is the indigenous people of Masai Mara. The Masai Mara tribe have lived in harmony with the animals for over four centuries. However, when the game parks were created they were forced to move without compensation. Revenue from this park have not flowed proportionality to the tribes. These negative effects have created a lot of conflict for the Masai Mara tribe. As documented above, ecotourism is vital for the economy, lifestyle and on going maintenance of wildlife in Kenya. What is required is a balanced approach to sustainability of ecotourism. Ecotourism in Kenya and in any location of the world should have minimum impact on the indigenous culture, a steady income stream and reduction on land degradation and wildlife destruction. The revenue of tourism should support the lives of the grass root people and enable them to have suitable standards of living. This will encourage their commitments to programs as they will see the benefits of their co-operation. The specific initiatives that should be looked at include an increase in tour prices during peak season as it will generate an even flow of tourists each year. Non-motorised vehicles, such as microlight flights and hot air balloons should be used for tourists to explore the wildlife as they create no pollution. Also, the management of parks need to be cared for by promoting campaigns and raising awareness to all tourists about the effects of littering and pollution of the fragile ecosystem. Kenya needs sustainable ecotourism for its survival on the economy. Kenya needs to develop strategies that will have minimal effects on social, cultural and the ecological environment. If the initiatives above are followed, it will ensure that the future generation of the world will still be able to enjoy one of the last undisturbed natural environments.

Is the World Wide Web Causing a World Wide Woe - 1035 Words

Many people view the internet as the World Wide Web, connecting the population together and sharing information on a global scale. However, others look at it as a grotesque web that is entangling humanity with unintelligence. Whether positive or negative, it is indubitable that in the past years, society has become extremely reliant upon the internet. Every day, millions of people around the world use the internet for many different purposes: commerce, communication, social networking, work, education, entertainment, and more. Because the internet is used on a daily basis while providing graphic stimulation and frequent distractions, certain individuals are starting to believe that it can change the way people think. Indeed, â€Å"China†¦show more content†¦Perhaps one of the greatest significance of social networking websites is the incredible capability to stay connected with people. On the other hand, it could be argued that internet-based relationships are much les s personal than traditional methods of communication, potentially leading to problems with communicational behavior within a social setting. Due to the numerous distractions and advertisements presented by the internet, studies suggest a connection between internet use and ADHD: 32% of internet â€Å"addicts† had ADHD compared to only 8% of those with normal usage (Greenblatt). Furthermore, â€Å"Memorizing has become a lost art as we have moved from cramming our brains to cramming our hard drives,† (Greenblatt). This implies that many students today don’t even try to learn because anything that they want to know is at their fingertips. As fast as the internet has changed, people’s use and abuse of the web has grown and continues to expand. Clearly, the internet has generated significant technological and interactive advances in the past years. There are countless advantages as it relates to education, business, technology, and personal improvement. The internet’s storage capacity increases daily, resulting in immediate access to new information as well as new methods of communication. In educational settings, the internet has enhancedShow MoreRelatedEssay The History of Gambling in Ancient Civilizations3908 Words   |  16 Pageslook north,’ thus using the astragali to plumb the future.   But after the hunt, the hunters might cast bones to determine who went home with the most desirable cuts,† (Schwartz, 7). Divination was only the beginning. The first civilization in the world, Mesopotamia, was also the first civilization to gamble. Mesopotamian fortune-tellers filed down their hucklebones, originally used for divination, and marked them with insignia, taking the first steps toward a modern die (Schwartz, 8). EventuallyRead MoreMarketing Mistakes and Successes175322 Words   |  702 Pagesrespectively, and have been widely translated. In 1992 Professor Hartley wrote Business Ethics: Violations of the Public Trust. Business Ethics Mistakes and Successes was published in 2005. He is listed in Who’s Who in America, and Who’s Who in the World. vii This page intentionally left blank CONTENTS Preface About the Author Chapter 1 Introduction PART I ENTREPRENEURIAL ADVENTURES Chapter 2 Chapter 3 Chapter 4 Google: An Entrepreneurial Juggernaut Starbucks: A Paragon