1.Identify and review some of the strategies which the company uses to Essay

1.Identify and review some of the strategies which the company uses to deal with the difficulties presented by the specific features of financial services marketing - Essay Example The researcher is taking American International Group Inc. which is a U.S.A. based company for reviewing their products and strategies. In this paper the researcher is trying to identify the strategies which they use to deal with the difficulties presented by the features of marketing of financial services. The researcher will use the website of AIG and some journals for analyze the strategies of the company. American International group which is a financial services company constitutes of different business units. These are AIG Bank, AIG Direct, SunAmerica financial group, Chartis insurance, United Guaranty Corporation and International Lease Finance Corporation. The main revenue of the company is from the Chartis insurance which is major name in the global insurance sector. SunAmerica financial group is the other which generates maximum revenue for the AIG group. From this statistics it can be said that the company is mainly focusing on the life insurance, general insurance, wealth management, asset management programs. It can also be said statistics that the major percentage of revenue comes from the casualty and specialty line of business. In any type of industry the companies should design and offer the product or services according to the customer needs. Financial services industry is a volatile industry. During the economic downturn the companies generally don’t profit much from the financial services. The reputation of the companies plays a big role in that situation. If the financial services companies provide the products according to the needs of the customers and build customer loyalty then they will have a competitive edge than their competitors. For having a good percentage of market shares as well as retaining the customers in time of financial downturn a loyal customer base is necessary for the financial services company (The Economist, 2008, p.5-7). The services

Hospitality Contract and Event Management Assignment

Hospitality Contract and Event Management - Assignment Example The key factor that leads to a person contracting a caterer is because of his expertise in the sector. The person believes that he is being involved with a professional in the provision of the various services needed. A keen caterer would not compromise on his/her quality of product and provision of his/her services since he/she is there to get another contract or be recommended for his quality of his products and services.(Judge Advocate General's School (United States. Army), American Bar Association. Section of Public Contract Law2007) Another crucial characteristic is the manner he/she offers his/her services. Apart from the fact that the services should be of high quality, they should be offered at a considerable price and at the right time. The pricing of a caterer’s product and services should be considerable and effective free from hidden charges. These ensure that the caterer remains competitive and wins most of the contracts in the market. Another key feature that is crucial as far as provision of services is considered is the punctuality of his/her services. The services should be at the right place, at the right time with the right people offering those services. Another main characteristic that features in a catering contract is the innovation and new brilliant ideas. Catering sector is a competitive sector that requires caterer to be on their toes. Due to the fact that it is a dynamic sector makes it paramount to venture into new ideas that will attract customer for your products and services. They should offer the latest recipe of food, the latest outdoor design and interior design that satisfies the customers (Judge Advocate General's School (United States. Army), American Bar Association. Section of Public Contract Law2007) What caterer should be interested in is the satisfaction of his/her client. He/she should be pay attention to the way he/she prices his/her products, the way they deliver their products the quality of their products a nd the way they remain relevant I the sector. External factors affecting planning and management in the event and contract sectors Introduction. A hospitality sector which includes event planners and caterers is affected by internal and external factors just like other business enterprises. Internal factors such as management, finances, the level of safety menu among other actors plays an important role in the functioning of this sector. There are other uncontrollable factors which are external but can be controlled by planning well and sound management. One of such factors is the performance of the economy of a country. A well performing economy with sable prices, availability of skilled labor, flexible tax policies, performance of macro institutions, ease to put and run businesses and stable foreign exchange usually affects the smooth running of a business in the catering sector. When foreign exchange is unstable, prices are high, reduced expenditure by the government usually affe cts hospitality sector in the negative since there is reduced transaction (Anton S, Bryn P 1987) Hospitality sector is established and operates within the laws of a country. The law gives the licensing and gives the guidelines on how to operate in the sector. There are different laws such as laws that govern the t environment that do affect the hospitality

The Marketing Plan Research Paper Example | Topics and Well Written Essays - 1250 words

The Marketing Plan - Research Paper Example The market is therefore stable and still promises to grow. Every product producer and service provider has a unique way of marketing. The uniqueness of the marketing structure therefore promises either a profitable venture or a loss-ridden one. Depo-Provera, medically known as depot medroxyprogesterone acetate (DMPA), is a hormone injection that alters the production of estrogen. It therefore prevents a woman from producing ova. The product has been in the market and continues to expand to newer ones across the world (Frey, 1956). Situational analysis The market for contraceptive products continues to grow if not stable. The married, for instance, have an obligation of regulating the number of children they have depending on their financial stability and social preferences. The married form the greatest market shareholders. Because of their obligations, they shop for the most appropriate contraceptive methods. Additionally, the market is also composed of any other mature sexually act ive person within the country. However, the product targets those who have sexual intercourse regularly and is therefore more advisable on the married or commercial sex workers. Currently, there are a number of products in the market that provide similar functions. The most common of these include Nuvaring, another is Intrauterine Device (IUD) while Ortho Evra (patch) together with birth Pills also form part of these. All these and many others have their strengths and weaknesses that make them hold the market shares they currently dominate. As the market continues to grow, Depo-Provera continues to expand its market share which is a clear show of effective marketing strategies by the marketers of the company. Depo-Provera has a number of strengths which it has used as its competitive advantages over the years. Unlike other contraceptives, Depo-Provera is not used daily. A single injection lasts a month. This is a relief to many women who use the daily injections or the daily pills w hich normally tend to have severe bodily reactions. The monthly menstrual flow is a bother to many women; the hormonal injection alters the body making a woman miss her periods for three consecutive months (Abrams & Eugene, 2003). Additionally, the use of the injection is proven to reduce the chances of a woman suffering from ovarian cancer. Some of the used contraceptives normally have side effects some of which are as acute as the contraction of ovarian cancer. The use of Depo-Provera minimizes this risk thereby providing its user with the peace of mind and longevity of use. However, the product, just as any other in the market, presents a number of side effects, which also sum up as its weaknesses. Being a hormone, the injection reduces the thickness of the uterine lining. This results in reduced rates of the monthly bleeding and after a prolonged use, some women experience no bleeding at all. Such occurrence may affect the mental stability of many women who consider it normal fo r a woman to experience the monthly period especially when not using a contraceptive. Women may also after stopping the use of this contraceptive experience an excessive bleeding. This is normally because of the hormonal imbalance which is rectified through medication. The expansion strategy of the product is governed by a

Soc Essay Example | Topics and Well Written Essays - 750 words

Soc - Essay Example I once attended a celebration of a Chinese new year which they call Kung Hei Fat Choi which is really a different celebration of New Year from my culture. For one, the celebration was replete with firecrackers and loud noises in their belief to scare away bad omens. They also had a dragon dance which they believe to bring good luck and rounded foods. This type of celebration is considered alien to me because we do not do dragon dance in celebrating New Year nor prepare round foods. To explain my seeming alienation about Chinese New Year, I would like to bring about George Herbert Mead’s social psychological theory of relation among the mind that not all factors in my environment can influence how I think. I belong to _____(your primary group) as my primary group and ____(your formal organization) as my formal organization. I am basically comfortable with my primary group albeit it has no formal structure where other people of the group, including myself are just enjoying each other’s company. The formal group on the other hand is more structured and has an objective why it exists. It reflects the normative organization because there are rules that are expected to follow where its members are expected to conform. In the primary group, my status varies since the structure is informal. Sometimes I am the leader and opinion maker sometimes I am the follower depending on the situation. In the formal organization however, my status is labeled as a member because I am not an officer of that club. At the end of the game, I belonged to the middle class because I had enough property to sustain me in the game. The game basically made me realized that if you make enough investment early in the game, you will end up rich because when other players step into your property, they have to pay rent and this accumulates as the game goes. Having enough resources in the game made me realized that it will enable the player to

Declining Economic and Military Power Essay Example for Free

Declining Economic and Military Power Essay As the United States prepared to enter the twenty-first century, it could reflect upon the fact that the twentieth century was truly the American century, even with its declining economic hegemony and resulting lose of military hegemony. The U. S. entry into World War I tilted the balance against the triple alliance. It was the U. S. forces that played the major part in the defeat of the Axis powers in World War II . It was the U. S.men and material that contained Soviet Communist expansion until it self-destructed. Even though its military power was unrivaled, the United States had to confront the re-emergence of traditional isolationism at home, the creation of shifting coalitions around the world, and most importantly, its declining economic power in the world. In the 1940s and the 1950s, the United States was extraordinarily competitive in the world market . Virtually anything it produced, it could sell. Although partly the aftermath of World War II, which had destroyed most of America’s industrial competitors, this situation also reflected an American monopoly in high-technology industries and American productivity in lower-technology ones. The United States had a handsome surplus in its international balance of trade, and this surplus could in turn finance large-scale expenditures on U. S. military forces to be deployed overseas in the territories of America’s allies, including West Germany, Britain, Italy and Japan. A productive and competitive economy with high employment also provided a healthy base for federal taxation and spending. In such a happy condition, the United States could maintain a vast system of military alliances and spend 10 percent of its GNP on defense. In the slogan of the Eisenhower administration , the former was underwritten by the latter. Then all this started to change with seeming suddenness. Japan appeared to surge forward at incredible speed. Through the 1970s it’s rising indices of industrial production seemed to propel it above the industrial levels of the United Kingdom, the European Community, the Untied States. As the Soviet Union faltered and then collapsed, Japan and subsequently also West Germany increasingly became the symbols of so-called young economies, in which â€Å"organized capitalism† could achieve miracles which old capitalism could no longer deliver. The inventory of China and Japan’s successes was stressed frequently . Its rapid pace of economic growth, its systematic allocation of vast resources to gross fixed capital formation, its obvious progress in high-tech consumer-oriented production, and its impressive penetration of the global markets all received their due. In contrast, the United States was increasingly depicted as an aging, stumbling giant, losing its preeminence and its leading abilities. From the mid 1970s on, a vast literature asserted with much conviction that the United States was â€Å"deindustrializing,† losing the battle of high tech and unduly shifting its labor force toward services while complacently accommodating itself to falling productivity, low rates of saving, low rates of capital formation, failure in export markets, incessant trade deficits, and growing international indebtedness . If we simply add together economic and military power there is little doubt that the United States remains the hegemon. But it is important to recognize that military hegemon is dependent on economic hegemony, because the military is wildly expensive. Declining economic hegemony creates pressure to cut back on military expenditures. This pressure has been temporarily relieved because of the recent economic growth and the new revenues available to the U. S. federal state. However, it is doubtful that this trend of relatively greater economic growth will continue. Indeed, a collapse of the stock bubble could lead to a U. S. economic crisis that would force a major restructuring of its military capabilities and increase the pressure for other core states to take up the slack. Whether this happens quickly or slowly, predictions show that U. S. economic hegemony will continue to decline, and its military hegemony will follow. This will lead to a new period in which economic power and military power come once again to be recalibrated in a system of more equally powerful and competing core states. This current situation is almost similar in most structural respects to that at the end of the nineteenth century. Declining Britain was still advocating free trade, while the other core states and upwardly mobile semi-peripheries were shifting back to economic nationalism and protectionism. By arguing whether or not this happens in the next few years and to what could prevent another cycle of war over world leadership in the last chapter, a new window of vulnerability to warfare among core states will arrive. The institutional structures of global collective security will again be tested. It is in all humanity’s interest that these institutions be strong enough to prevent another war among core states. With the termination of the Soviet Union and the Soviet Empire in the early 1990s, it became clear that there were no large specific military threats facing the United States . As General Colin Powell, the chairman of the Joint Chiefs of Staff (JCS) from 1898 to 1993, noted in early 1992, the real threat we (the United States) now face is the threat of the unknown, the uncertain. Moreover, despite reductions in its defense capabilities from their Cold War levels, the United States was still far superior militarily to any nation or likely combination of nations in the world. The challenge for the United States was to maintain the sufficient order in the international system so that it could pursue its economic interests. At the end of the Cold War, the United States became one of the largest importer and exporter . Its economic well-being was consequently almost totally dependent upon the absence of chaos in the international arena. Since no one nation posed a specific military threat to the United States like the Soviet Union during the Cold War, the Pentagon was compelled to develop illustrative situations or scenarios in which American interests could be sufficiently jeopardized so that military force would have to be used. Before, there were also seven scenarios created in order to illustrate possibilities of a withdrawal of an attack on Iraqi or a battle plan on Baghdad . In early 1992, the Pentagon developed seven more scenarios with regards to the countries that could launch an attack against them. The first scenario is a repeat of the Iraqi invasion of Kuwait. This scenario assumes that sometime in the mid 1990s, the world’s support for the embargo against Iraq slackens, the regime in Iraq rebuilds its military to 1990 levels, and launches a blitzkrieg attack southward. Unlike August 1990, the Iraqis do not stop at the Saudi border, but move into northeastern Saudi Arabia and take control of its oil fields and major export terminals before the United States and its coalition forces can respond. The second illustrative scenario involves an all-out attack on South Korea by some 300,000 North Koreans. To help the South Korean forces counter this invasion, the United States would deploy five combat divisions to augment South Korea’s 800,000-man army. In addition, this nation would send five aircraft carrier battle groups, two Marine expeditionary forces and 20 land-based air squadrons. This force of about 250,000 Americans and 1 million South Koreans would take about three months to prevail against the forces of Kim II Sung. The third scenario is a combination of the first two. It assumes that the Iraqi and North Korean invasions occur simultaneously and that the United States has to fight a two-front war with over 500,000 people, some 5,000 miles apart. The fourth scenario involves an invasion of the Baltics by an expansionist, authoritarian government in Russia . The Pentagon postulates that 18 Russian and six Belarusian divisions would attack along the Lithuanian-Polish border to â€Å"protect Russian minorities† living in the Baltics. To respond to this situation, the U. S. would deploy seven combat divisions, 49 land-based air squadrons, six aircraft battle groups, and a Marine expeditionary force. Augmented by an additional 11 ground-divisions and 17 tactical fighter squadrons from NATO, Western forces would prevail in three months. The fifth and sixth scenarios involve one-wee invasions of the Philippines and Panama. The invasion of the Philippines by Marine amphibious forces and army paratroopers is made necessary by the chaos that results from a failed coup and endangers some 5,000 Americans in Manila. The Panamanian invasion of airborne and amphibious troops follows from an attempt by rightwing elements close the Panama Canal. The final scenario is based on the possibility that in the next century a resurgent Russia or an emerging superpower adapts an adversarial military strategy and capability to threaten U. S. interests around the world. The U. S. response would be to reconstitute its Cold War military force and its alliance strategy. The first and second scenarios were also the focus of the Clinton Administration’s Bottom-Up Review, published in September 1993. Despite all these scenarios and the decline in both economic and military hegemony, the United States can still be considered to be on top of its league. In addition to this, the end of the Cold War resulted to the shifting of budget due to the cutting or decrease of military budget . Despite the decrease in the economy of the United States and the rapid growth of its competitors such as China, still, the GDP of United States is greater . As such, just like a spring, it can be said that United States is merely pulling itself back in order to spring further beyond the others. References Switzerland (10/07). (October 2007). Retrieved March 9, 2008, from http://www. state. gov/r/pa/ei/bgn/3431. htm Bay, A.(July 18, 2007). Iraqi Withdrawal: Seven Scenarios [Electronic Version]. Strategy Page. Retrieved March 9, 2008, from http://www. strategypage. com/on_point/200771813240. aspx Binnendijk, H. , Simon, J. (December 1995). Baltic Security and NATO Enlargment. Retrieved March 9, 2008, from http://www. ndu. edu/inss/Strforum/SF_57/forum57. html Calleo, D. (2005). Hegemony and Decline: Reflections on Recent American Experience. March 9, 2008, from http://www. sens-public. org/spip. php? page=imprimersansid_article=138 Ching, P. -y. (December 9, 2006). American Imperialism and its Domination Over Asia. Retrieved March 9, 2008, from http://www. aprnet. org/ Corn, D. , Perry, M. (April 3, 2003). The Battle Plan for Baghdad? Washington Post. Huntington, S. P. (Winter 1988/89). The U. S. Decline or Renewal? Foreign Affairs. Pianta, M. (1988). New Technologies Across the Atlantic. Retrieved March 9, 2008, from http://www. unu. edu/unupress/unupbooks/uu38ne/uu38ne00. htm#Contents Shaplen, J. T. , Laney, J. (December 2007). The Decline of U. S. Power in Northeast Asia [Electronic Version]. Washingtons Eastern Sunset. Retrieved March 9, 2008, from http://www. foreignaffairs. org/20071101faessay86606/jason-t-shaplen-james-laney/washington-s-eastern-sunset. html Spring, B. (June 2, 1998). House Resolution Tells President: Defend All Americans from Missile Attack. Retrieved March 9, 2008, from http://www. heritage. org/Research/MissileDefense/EM530. cfm Taylor, C. W. (1993). Alternative World Scenarios for a New Order of Nations: DIANE Publishing. Woolley, J. T. , Peters, G. The American Presidency Project. Retrieved March 9, 2008, from http://www. presidency. ucsb. edu/ws/index. php? pid=10120.

China today Essay Example for Free

China today Essay China today would not miss the inquisitive recognition of an observative eye. Ranging from the political, economical and social, China has moved from some of its early concepts, thoughts, philosophies and forms of ruling. Today, much more influence from the outside world has had major impact on the outlook of the modern Chinese people and their culture. To talk about China without reflecting about their ancient culture and the dynasties would be to do a great injustice to the Chinese people. Although, the concern of this essay is to look at individualism, thus it would be not possible not to generally mention the emperors ruling and the culture which has dominated China since 221 BCE. The Chinese society was largely an agricultural settled society that was propagated by the Confucius thought. Many of those who have written the history of China have at instances tried to compartmentalize it into culture, politics and society. This loses the value of their study since being a Chinese before the eighteenth and nineteenth century involved culturalism as opposed to nationalism. These are a people who largely had a shared identity and collective rituals. Confucius ideas, self development, among others and negative attitude to profit making had an impact and an expression of individualism. Culturalism impeded the growth of the state because it emphasized on ones ties to the family, region or city. In other words China was fragile due to ethnic nationalism which made it a very unstable state especially under the poke of other countries. The ethnic nationalism was responsible for the revolution of the 1911 because of anti Manchurian Han oriented ideas that they, Manchuria courts were not in a position to defend the Chinese people. It is at the twentieth century that China was faced by threats from Western and Japanese capitalism and imperialism. Therefore it had to define its position on the national stage and set itself a much a country to be consulted in matters of the world (Wang, pp ix 211). The importance of the individualistic view in the Confucianism tradition helped to set China in preparation of later developments and changing realities that could not allow it to retain the empire style. Thus, it is by the negation of Confucius ideas that led to the rise of new culture thus the birth of state nationalism. Closely following this era is the period of Chairman Mao who was an ardent socialist. During his time era, from 1949 it was considered behaving like a bourgeoisie when one showed interests in self. China was a collectivist state that suppressed the individual desires advocating for the society’s plight. The changes in China today are as a result of the government outlook reforms of the 1980’s. Mostly the youth in China mirror more of the Western culture more than the older generation thus sometimes causing conflict between the two groups. The Western culture has brought individualistic thought and perspectives that even in education politics and all other parts of the society reflect an outlook of self. In education as an example most the parents are urging the sons and daughters to pursue high paying courses for the sole purpose of personal better placement. Post Mao China has overcome the collective notions of the society to emphasis on individualism. No longer will you see workers donning the same color or style clothes (Robert, para 8, 9 10). The fact that the modern Chinese society was formed on the foundations of the West does not mean that the Confucius thought completely was exterminated. The power of the community is still in force as Wei-ming Tu puts it, that there is group solidarity which is involved decision making through consensus can d conflict resolutions. There is no distinction between personal and public lives of the people. The classical outlook of the family by the Confucius thought still forms as the major connection of politics education capitalism and social lives. This has the implications of a sense of duty responsibility obligation relationship independence and autonomy. Thus, in the wake of being the best person through self respect and dignity such a person does not fall short of having the role of taking care of his fellow neighbor family community state and the state. This is seen as the modern psychological approach to the new China in the fact that if one is found falling less of this, then you loose your place in the public hence a sense of personal guilt. It is therefore evident that the Chinese value collective individualistic aspects for the betterment of the society (Tu, pp 7, 8, 9 10). Bibliography: Robert L. , M. Ethnology: Generation KU: individualism and Chinas millennial youth, 22nd September 2005. Retrieved from http://goliath. ecnext. com/coms2/gi_0199-5616321/Generation-KU-individualism-and-China. html#readmore on 25th April 2009 Tu, W. Confucian Traditions in East Asian Modernity: Moral Education and Economic Culture in Japan and the Four Mini-Dragons. ISBN 0674160878, 9780674160873, Harvard University Press, 1996. Wang, K. Modern China: An Encyclopedia of History, Culture, and Nationalism. ISBN 0815307209, 9780815307204, Published by Taylor Francis, 1998.

What Is A Buffer Biology Essay

What Is A Buffer Biology Essay A  buffer  is an  aqueous solution  that has a highly stable  pH. If you add  acid  or  base  to a buffered solution, its pH will not change significantly. Similarly, adding water to a buffer or allowing water to evaporate will not change the pH of a buffer. A buffer is a substance in a solution that can neutralize either an acid or a base. A substance is said to be naturally buffered if it has a buffering action in its natural state .Buffers are used in chemistry to modulate and stabilize the pH of a solution. A buffered solution can be made in a variety of ways, most simply by creating a mixture of a weak acid and its conjugate base. Buffers are chemicals that, when added to water, tend to maintain a certain pH. This is due to the buffers ability to either accept or donate a proton (hydrogen ion, H+) or hydroxyl (OH-) to keep the pH in a certain range. Buffers are different than strong acids and bases because buffers do not donate all of their protons or hydroxyls within their buffering range. A buffer is a substance, usually a salt, that can bind with either the positively-charged hydrogen ion of an acid or the negatively-charged hydroxide ion of a base. If a solution is buffered, acids or bases can be added to the solution without changing its pH as drastically as if the acid or base were added to an unbuffered solution Natural Buffers A solution is said to be naturally buffered if it contains buffering compounds as it exists in nature. Blood is an example of a naturally buffered solution. Blood must maintain a pH close to 7.4 in order to carry oxygen effectively and contains compounds that react to acids or bases in order to neutralize them.   PREPERATION OF BUFFER A compound can buffer the pH of a solution only when its concentration is sufficient and when the pH of the solution is close (within about one pH unit) to its pKa.   To make a buffer you must first pick a compound whose pKa  Ã‚   is close to the pH   you want for the solution, and then decide what the buffer concentration should be.   Typically, buffer concentrations are between 1 mM and 200 mM, depending on the desired ionic strength and the buffering capacity required.   If the pH is expected to decrease during the experiment, choose a buffer with a pKa  slightly below the working pH.   Conversely, if the pH is expected to increase during the experiment, select a buffer with a pKa  slightly above the working pH.   Having decided on the total buffer concentration, you must adjust the ratio of the protonated and unprotonated forms of the buffer in your solution so as to give the desired pH.   Typically, buffers are composed of   weak acids and their salts, or w eak bases and their salts.   If the protonated form is uncharged, it is an acid (like acetic acid), and its unprotonated form is a salt (e.g., sodium acetate).   Conversely, if the unprotonated form is uncharged it is a base (like Tris base), and its protonated form is a salt (e.g., TrisHCl). Four practical ways to make a buffer are described below: The Slow and Stupid Method    To avoid adding extra salt to a solution, prepare a buffer composed of an acid and its salt by dissolving the acid form of the buffer in about ~60% of the water required for the final solution volume.   Adjust the pH using a strong base, such as NaOH.   When preparing a buffer composed of a base and its salt, start with the base form and adjust the pH with strong acid, such as HCl.   After the pH is correct, dilute to just under the final solution volume.   Check the pH and correct if necessary, then add water to the final volume.   Advantages:  Easy to understand.   Disadvantages:  Slow.   May require lots of base (or acid).   If the base (or acid) is concentrated, it is easy to overshoot the pH. If the base (or acid) is dilute, it is easy to overshoot the volume.   Ionic strength will be unknown. Adding a strong acid or base can result in temperature changes, which will make pH readings inaccurate (due to its dependence to temperature) unless the solution is brought back to its initial temperature.   (2)The Mentally Taxing Method   Using the buffer pKa  , calculate the amounts (in moles) of acid/salt or base/salt present in the buffer at the desired pH.   If both forms (i.e., the acid and the salt) are available, convert the amount required from moles to grams, using the molecular weight of that component, and the weigh out the correct amounts of   both forms.   If only one form is available, you can prepare the buffer by adding all of the buffer as one form, and then adding acid or base to convert some of the added buffer to the other form.   Decide what the total concentration of buffer will be in the solution, and convert the concentration to amount (in moles) using the volume of solution, and then to grams, using the molecular weight of the buffer form available.   Then calculate the amounts (in moles) of each form that will be present in the final solution, using the buffer pKa  Ã‚  and the desired pH.  Ã‚   Then calculate how much strong acid or base must be added to convert enough of the buffer form added to the other form,   to give the correct amounts of each form at the pH of the final solution.   Dissolve the buffer and strong acid or base in slightly less water than is required for the final solution volume.   Check the pH and correct if necessary.   Add water to the final volume. Advantages:  Fast.   Easy to prepare.   Additional pH adjustment is rarely necessary, and when necessary, the adjustment is small. Ionic strength easily calculated. The Two Solution Method   Make separate solutions of   the acid form and base form of the buffer, both solutions having   the same buffer concentration (and ionic strength, if required) as the concentration of total buffer in the final solution.   To obtain the desired pH, add one solution to the other while monitoring the pH with a pH meter.   Advantages:   Easy to do.   Disadvantages:  Requires both forms of buffer.   The required solution volumes are proportional to the ratio of buffer components in the final solution at the desired final pH, so making equal amounts of each form may waste a lot of one solution. The Completely Mindless Method   Find a table of the correct amounts of acid/salt or base/salt required for different pHs, and dissolve the components in slightly less water than is required for the final solution volume.   Check that the pH and correct if necessary. Add water to the final volume.   Advantages:  Easy to do (with appropriate table).   Convenient for frequently prepared buffers.   Disadvantages:  May be impossible to find table.   Table may be incorrect.   Requires both forms of buffer.   Component amounts from table will need to be adjusted to give the buffer concentration and volume in your solution. Ionic strength is unknown.   Common Buffer Preparations   Buffer Stock Soln Components Amount per Liter Soln. Conc. Stock Soln Final Conc.   PBS  Ã‚   (Phosphate Buffered Saline)  Ã‚   adj. pH ~7.3   10X NaCl  Ã‚   KCl  Ã‚   Na2HPO4Æ’Æ’-7H2O  Ã‚   KH2PO4   80 g  Ã‚     Ãƒâ€šÃ‚   2 g  Ã‚     11.5 g  Ã‚     Ãƒâ€šÃ‚   2 g   1.37 M  Ã‚     Ãƒâ€šÃ‚   27 mM  Ã‚     Ãƒâ€šÃ‚   43 mM  Ã‚     Ãƒâ€šÃ‚   14 mM 137 mM  Ã‚     Ãƒâ€šÃ‚  Ãƒâ€šÃ‚   2.7 mM  Ã‚     Ãƒâ€šÃ‚  Ãƒâ€šÃ‚   4.3 mM  Ã‚     Ãƒâ€šÃ‚  Ãƒâ€šÃ‚   1.4 Mm   SSC  Ã‚   adj. pH ~7.0   20X NaCl  Ã‚   Sodium citrate   175 g  Ã‚     Ãƒâ€šÃ‚   88 g   3 M  Ã‚     0.3 M   150 mM  Ã‚     Ãƒâ€šÃ‚   15 Mm   STE   (Saline Tris EDTA)     1X Tris base  Ã‚   NaCl  Ã‚   EDTA (acid)    1.2 g  Ã‚      0.6 g  Ã‚      0.29 g   10 mM  Ã‚     10 mM  Ã‚     Ãƒâ€šÃ‚   1 mM   10 mM  Ã‚     10 mM  Ã‚     Ãƒâ€šÃ‚   1 mM   TAE  Ã‚   (Tris acetate EDTA)  Ã‚   pH ~8.5   50X Tris base  Ã‚   Acetic acid (glacial)  Ã‚   EDTA   242 g  Ã‚     Ãƒâ€šÃ‚   57.1 mL    37.2 g     2 M (Tris acetate) 0.1 M      40 mM (Tris acetate)  Ã‚     Ãƒâ€šÃ‚   2 mM   TBE   (Tris borate EDTA)  Ã‚   pH ~8.0   10X   Tris base  Ã‚     Boric acid  Ã‚     EDTA   108 g  Ã‚     Ãƒâ€šÃ‚   55 g  Ã‚     Ãƒâ€šÃ‚   40 mL   (0.5 M pH 8)     0.89 M  Ã‚     0.89 M  Ã‚     0.02 M   89 mM  Ã‚     89 mM  Ã‚     Ãƒâ€šÃ‚   2 mM   TE  Ã‚   (Tris EDTA)  Ã‚   pH ~7.5   1X Tris base  Ã‚   H2  EDTA (acid)   1.2 g  Ã‚     0.29 g   10 mM  Ã‚     Ãƒâ€šÃ‚   1 mM   Useful buffer mixtures Components pH range HCl,  Sodium citrate 1 5 Citric acid,  Sodium citrate 2.5 5.6 Acetic acid,  Sodium acetate 3.7 5.6 K2HPO4,  KH2PO4 5.8 8  [3] Na2HPO4,  NaH2PO4 6 7.5  [4] Borax,  Sodium hydroxide 9.2 11   Universal buffer mixtures By combining substances with pKa  values differing by only two or less and adjusting the pH a wide-range of buffers can be obtained.  Citric acid  is a useful component of a buffer mixture because it has three pKa  values, separated by less than two. The buffer range can be extended by adding other buffering agents. The following two-component mixtures (McIlvaines buffer solutions) have a buffer range of pH 3 to 8. 0.2M Na2HPO4  /mL 0.1M Citric Acid /Ml pH 20.55 79.45 3.0 38.55 61.45 4.0 51.50 48.50 5.0 63.15 36.85 6.0 82.35 17.65 7.0 97.25 2.75 8.0 A mixture containing  citric acid,  potassium dihydrogen phosphate,  boric acid, and  diethyl barbituric acid  can be made to cover the pH range 2.6 to 12.[6] Other universal buffers are  Carmody buffer  and  Britton-Robinson buffer, developed in 1931. Significance:- An important number for any aqueous solution is its pH. The pH is the negative logarithm of the concentration of hydrogen ions (often represented as a hydronium ion, which is a water molecule with an extra proton attached). Anything with a pH of less than 7 is considered to be acidic, and a solution that has a pH of greater than 7 is basic. Pure water, which has an equal amount of acid and base in it, is defined as having a pH of 7. Identification:- Buffered solutions are used to make a solution that exhibits very little change in its pH when small amounts of an acid or base are added to it. A buffer can be made by addition of a weak acid and its conjugate base to a solution. Alternately, a weak base and its conjugate acid can be used. Buffers are most effective when the amounts of the weak acid/base and the conjugate base/acid are usedgenerally to be effective, neither quantity should be more than 10 times that of the other. Control of ph by buffer Buffers are chemicals that, when added to water, tend to maintain a certain pH. This is due to the buffers ability to either accept or donate a proton (hydrogen ion, H+) or hydroxyl (OH-) to keep the pH in a certain range. Buffers are different than strong acids and bases because buffers do not donate all of their protons or hydroxyls within their buffering range. Background:- The measure of pH gives the concentration of hydrogen ions in a solution. Pure water has a pH of 7.0 and has an equal balance of hydrogen ions and hydroxyl ions. The pH will be lower if an acid is added and higher if a base is added. For various purposes, it is useful to add a buffer so that the pH remains constant even if an acid or base is added to the solution. Buffers are used to maintain constant pH. Buffer Equilibrium:- Different buffers  work  at different pHs. A buffer is most efficient at maintaining a constant pH when the pH equals its acid dissociation constant, its pKa. At this pH, the buffer consists of an equal solution of protonated and de-protonated conjugate base. This often denoted by a theoretical buffer molecule, AH, dissociating into a proton, H+, and the conjugate base, A-. The pKa is determined by the pH where the concentration of AH equals the concentration of A-. Buffering Acids:- At its pKa, a buffer can maintain a constant pH by accepting free protons. Adding an acid to the solution, such as HCl, will cause free protons to enter the solution. The conjugate base will accept the free protons, causing the pH to be unchanged. The solution will remain at the same pH as long as there is enough conjugate base to accept the additional protons. The reaction can be written as the dissolution of the acid: HCLH+ + Cl- leading to free H+ in the solution. The further reaction with the buffer occurs: H+ + A- HA. This removes the free protons and constant pH is maintained. Buffering Bases:- Adding a base such as sodium hydroxide to a solution will cause an increase in the hydroxyl concentration. In a buffered solution, the protons attached to the undissociated buffer are donated to the solution, forming H2O with the free hydroxyls. This counters the effect of the base and maintains the pH of the solution as long as there is undissociated buffer available in the solution. In this case, the reaction can be written as the dissolution of the base: NaOH Na+ + OH- leading to the second reaction of OH- + HA H2O + A-. Different Buffers:- Different buffers have different pKas and can be used to buffer solutions at a wide range of pHs. Chemicals used as buffers often have the ability to donate or accept multiple protons or bases. These buffers hence have two or more different pKas corresponding to how many protons or hydroxyls per molecule they can donate or accept. Different buffer molecules can be combined to form customized buffer ranges. For a list of biological buffers, see Resources. WORKING OF BUFFER When hydrogen ions are added to a buffer, they will be neutralized by the base in the buffer. Hydroxide ions will be neutralized by the acid. These neutralization reactions will not have much effect on the overall pH of the buffer solution. When you select an acid for a buffer solution, try to choose an acid that has a pKa  close to your desired pH. This will give your buffer nearly equivalent amounts of acid and conjugate base so it will be able to neutralize as much H+  and OH-  as possible. PURPOSE OF BUFFER:- A buffer solution is used to resist changes in pH when a certain amount of strong acid or base is added to the solution. It is an important part of biological systems in living organisms as well as in the laboratory. The reason a buffer works to maintain a certain pH is that the concentration of weak acid and base is kept in a specific ratio in line with the acid titration curve. The titration curve A titration curve is a graph that relates the relative concentrations of a weak acid to its conjugate base by graphing pH versus amount of base added. In the region of the titration curve where the graph is almost flat, the pH changes very little with added base and therefore this would be a good pH for the buffer. Buffer in cells and blood The main buffer found in living cells is the H2PO4/HPO4- buffer pair. In blood, the main buffer is the H2CO3/HCO3- pair. This system relies on dissociation of carbonic acid, which has a pKa of 6.37. The pH of human blood needs to remain at around a pH of 7.4 and therefore the system also involves carbon dioxide transported to the lungs. Phosphate buffer The phosphate buffer is based on tris (hydroxymethyl) aminomethane or TRIS. This buffer has a pKa of 8.3 and is found both in living organisms as well as used in the laboratory. It is a good buffer because it does not tend to interfere with the system being studied. Buffers in enzymatic reactions Laboratory methods to isolate an enzyme use buffered solutions because an enzyme can only function in a narrow pH range. Enzymes are very sensitive to pH as well as salt concentrations. Therefore, it is important to use a buffer with a very good buffering capacity for the specific pH in order for the experiment to be successful. Physiological consequences Respiration plays a role in buffering of blood by controlling the rate of respiration depending on the need for hydrogen ions or increased acidity. Increasing the rate of respiration is helpful when there is a buildup of hydrogen ions or acidity in the blood. The H+ ions bind to bicarbonate to form carbonic acid. This raises the level of carbon dioxide in the lungs. Increasing the level of respiration removes the excess carbon dioxide. Therefore, here the buffering system is used to keep pH level of the blood within the required narrow range. Features:- The pH of a buffered solution is defined by the Henderson-Hasselbalch equation, which states that the pH of a solution is equal to the acid dissociation constant of the weak acid plus the logarithm of the ratio of the concentrations of conjugate base to the weak acid. The acid dissociation constant is a number that defines the tendency of an acid to dissociate and form hydrogen ions. A strong acid will have a very low dissociation constant, whereas a weaker one may have a significantly higher one, around 5. Considerations:- Buffered solutions have many applications in chemical manufacturing for processes that require a specific pH range to  work. This is also true for the human body, which contains many enzymes that are only functional at a specific pH. Outside of this range, the enzymes are either unable to catalyze reactions, or in some case will misfold and become broken down; thus, a mixture of carbonic acid and bicarbonate is used by the body to keep pH of the blood between 7.35 and 7.45.