The Indirect Iodimetric Analysis Ascorbic Acid free essay sample

I: Purpose: To determine the percent weight of Ascorbic Acid in unknown sample. This was to be done by the means of an indirect iodimetric analysis. In an iodometric analysis, the oxidizing agent can be determined by a different means than titrating directly with standard iodide, because a high concentration of I- is needed to form the I3- complex. In this type of analysis, excess iodide is added to the oxidizing agent, and the triiodine is titrated with stand thiosulfate. This indirect analysis finds the number of moles of ascorbic acid based on the known number of moles of IO3- and subtracting half the amount of moles of the thiosulfate solution. II: Equations: Iodate with Iodide: IO3- + 8I- + 6H+ ? 3I3- + 3H2O Thiosulfate with Triiodide 2S2O32- + I3- ? S4O62- + 3I- Ascorbic Acid with Triiodide C6H8O6 + I3- +2H2O ? C6H6O6 +3I- + 2H3O+ III: Sample Calculations: A) Concentration Iodate: 1. We will write a custom essay sample on The Indirect Iodimetric Analysis Ascorbic Acid or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 9502g KIO3 * * = 0. 01823 M KIO3 B) Concentration Thiosulfate (S2O32-) 0. 0250481 L KIO3 * = 0. 00045663 mole KIO3 0. 00045663 moles IO3- * * = 0. 0027366 M C) First and Second Derivative V(mL) E(mV) ?V(mL) ?E ?E/? V ml ? ?(?  E/V) ?(? E/? V)/? Vav 14. 536 265 0. 021 -181. 25 -8629. 05 14. 5305 0. 01 -4 -400 14. 541 14. 546 261 0. 011 -100 -9090. 9 14. 5465 0. 012 -6 -500 14. 552 14. 558 255 0. 047 500 10638 14. 5555 First Derivative: On the y-axis plot ? E/? V (column 5) and on the x-axis plot ml (column 6). The slope is steepest at the end point. Second Derivative: On the y-axis plot ? (? E/? V)/? (column 9). And on the x-axis plot Vav (column 10), where the graph crosses zero is the end point. D) % Weight Ascorbic Acid (fully automated) -Moles Ascorbic Acid = moles I3- ? (moles S2O32-) -Mols IO32- = 0. 025048 L IO3- * * = 0. 001370 mols I3- -Mols S2042- 0.  014872L S2032- *0. 07151 M S2O42- = 0. 00106 mols S2O42- -Mols Ascorbic Acid = 0. 001370 moles I3- ? (1. 00106 moles S 2O62-)= 0. 000838 moles Ascorbic Acid 0. 000838 moles Ascorbic Acid * = 0. 1476 g AA % weight = *100 = 50. 18% IV: Tables and Graphs: See attached for first and second derivative and chart used to obtain first and second derivative. Semi-Manual Titration mL mV mL mV mL mV 0 3040 14. 342 287 14. 632 164 2. 030 339 14. 390 284 14. 642 156 4. 026 336 14. 484 275 14. 660 152 5. 970 334 14. 494 274 14. 676 147 8. 010 330 14. 504 272 14. 692 144 10. 004 326 14. 536 265 14. 706 140 12. 026 318 14. 546 261 14. 736 137 12. 650  314 14. 560 255 14. 764 133 13. 186 310 14. 570 247 14. 796 131 13. 428 308 14. 578 241 14. 816 128 13. 912 301 14. 580 236 14. 864 126 14. 106 296 14. 600 193 14. 930 123 14. 154 295 14. 612 174 15. 054 120 14. 296 289 14. 622 168 15. 868 112 V. Conclusion: After completing three separate methods to determine the percent weight of ascorbic acid in a sample, in the manual titration the percent weight was 51. 45%. The semi-manual method gave a percent weight of 51. 40%, and the automatic titration gave a percent weight of 50. 18%. Averaged together, giving a percent weight of 51. 01% and a standard deviation of 0. 719 and an RSD of 14 ppt. A possible systematic error that could have occurred would have been while doing the manual titration to not wipe the tip of your 25 mL pipet. This would have caused the calibrated amount to not have been correct and you would have added a falsely high amount of potassium iodate. This would have given a value of moles I3- higher than what was actually given. This is turn would create a larger value for the moles of ascorbic acid and you would get a higher percent weight. Another possible systematic error would be if the automatic titrator was improperly calibrated and it caused the volume dispensed to be larger than what was shown. This would have given an underestimation of the end point. For example, if the machine showed the it had reached the end point at 15. 00 mL but in realty the machine had dispersed 15. 02 mL. , which would lead to a number of moles of S2O32- that are lower than what was actually required, which would in turn give a lower percent weight of ascorbic acid and be falsely low. VI: Questions: 1. Explain the difference between iodimetric and idometric methods of analysis. Why is this experiment classified as an indirect iodimetric method? Iodimetric uses reducing agents to be determined by direct titration with standard I3-. Examples are As(III), sulfide, cyanide etc. , which contain oxidizable functional groups. Whereas idometric is used for the determination of oxidizing agents. Excess iodide is added to the oxidizing agent and the triiodide that’s produced is titrated with thiosulfate. This experiment is classified as an indirect iodimetric method because since we are measuring content of ascorbic acid through the known moles of thiosulfate and I3-, the method becomes indirect but it is also idoimetric because we are determining an oxidizing agent. 2. What is the function of the KIO3 solution? Explain how the preparation of this standard solution differs from the preparation of the standard NaOH solution used in the Soda Ash experiment. Iodate was used because in the idometric analysis, a high concentration of I- is needed, so excess iodine is added to the iodate to form the triiodine which is then titrated with thiosulfate. This differs from the soda ash experiment because in the soda ash experiment a primary standard (KHP) was used. 3. Use a balanced net ionic equation to explain the purpose of the KI in this experiment. Why must KI be present in excess? IO3- + 8I- + 6H+ ?  3I3- + 3H2O KI is in excess because a high concentration of I- is needed to form the triiodine which then allows the method to proceed with idometric analysis, where the I3- can be titrated with thiosulfate. 4. What is the function of thiosulfate? Write the balanced net ionic equation for the reaction of thiosulfate and triiodide. What pH range is required for this equation to hold? 2S2O32- + I3- ? S4O62- + 3I-. S2O42- is used for titration after it has been standardized which can be determined by the equation moles of ascorbic acid = moles I3- ? (moles thiosulfate). This complex is oxidized to S4O62- as log as the pH is below 9. 5. Describe the preparation and standardization of the thiosulfate solution including all special procedures. The solution is made from Na2S2O3 5H2O, but since it is not a primary standard, it must be standardized. The solution has the potential to be oxidized by atmospheric oxygen, so deionized water which is bubbled with nitrogen prior to the solution preparation. Adding a few drops of chloroform prevents bacteria which can cause decomposition. 17 g of Na2S2O3 5H2Om was added and filled with water that has been bubbled with nitrogen and 0. 05g Na2CO3. The solution is then mixed and the chloroform was added. Three spate flasks were used for standardization. Each flask contained excess solid KI. For the titration, when the color turned pale yellow, the starch indicator was added and the titration was complete when the blue color disappeared. 6. What is the indicator for titrations involving triioidine ion? Why is the indicator added just prior to the end point? When the yellow color turns pale, the helical amylase component of soluble starch is added. This indicator must be added after most of the triiodine has reacted because in large concentrations, the stable complex remains even after the end point is passed. 7. Give the common name and molecular formula for ascorbic acid. Write the balanced net ionic equation for the reaction of this compound with triiodide ion. The common name is Vitamin C and it has a molecular formula of C6H8O6. C6H8O6 + I3- +2H2O ? C6H6O6 +3I- + 2H3O+ 8. Explain what is meant by potentiometric end point detection. Describe data analyses by first and second derivative plots. Potentiometric end point detection, the end point is determined graphically and titrant is added in increments and the potential is measured. The first derivative is the change in voltage divided by the change in the titrant volume on the y-axis and it is plotted against the titrant volume midway between the two points. Where the slope is the steepest is the end point. The second derivative is the change in the first derivative divided by the change in the titrant volume midway between two points, on the y-axis and the average value of the midway titrant volume on the x-axis. The end point is where the graph crosses zero. 9. Explain the difference between an indicator electrode and a reference electrode. What items serve these functions in this experiment. An indicator electrode responds to changes in the activity of one of the ions in the solution, since it is impossible to measure a single electrode, a reference electrode is needed. The reference electrode remains constant, any changes are due to the indicator changes. 10. A possible source of systematic error in this experiment is partial decomposition of the thiosulfate solution. Suppose that decomposition occurred after the thiosulfate was standardized, but before it was used for analysis of ascorbic acid. Would the wt% ascorbic acid be falsely high, falsely low, or unaffected? Give all the reasoning to justify your answer. If the thiosulfate had decomposed after it had been standardized, it would have required more milliters of solution to titrate and obtain the same amount of moles since the concentration had been decreased. With more titrant being added, you are going to get a number of moles that is greater. Since to obtain the moles of ascorbic acid, you subtract the moles of the thiosulfate (divided by 2) from the moles of the IO3- you are subtracting a larger number and you are going to obtain a smaller number for the moles of ascorbic acid, thus the %wt would be falsely low.

Micro- and Macro-Sociology Essays

Micro- and Macro-Sociology Essays Micro- and Macro-Sociology Essay Micro- and Macro-Sociology Essay Hungarian Kay Track and One World under business Drabber Lovely hula hands by Hungarian Kay and One World Under business by Drabber, I find both articles very interesting and inter-related because it displays a connection in the micro- and macro sociology. Lovely hula hands can be analyzed from the micro sociology because it is concerned with daily human interaction such as social status, social role and social interrelations that take place in the central place of the article. The author does not generalize and abstract social trend but describes the real situation. One world under business concentrates more of the evolution of social structure related to macro sociology; his article contains not only sociological critiques but the product of the sociological imagination and levels of theoretical abstractions and also his contribution to the modern sociology today. I found both articles interesting because they have a unique relationship almost similar to an extent of again who has the power? Who has the Authority? Brings about impacts socially, economically, politically as well as culturally, and both articles face the same argument of authority and power. Lovely Hula Hands describes the modern life of the Hawaii from the Native Hawaiian point of view. Haunt Kay Track explores the cultural modification and exploitation of Hawaiian Culture including their language, dress and dance forms have been marketed as products for mass consumption of tourists (88). We know clearly that exploitation occurs when aspects of subculture, such as belief, ritual and social customs, are marketed without the cultural groups permission. And in todays world many racial ethnic groups like e. G Native America, Latino etc have experienced cultural exploitation and this is true today. We see people trapped in two worlds (culture) of which one is ours and the other one is forced upon us without any consent. And for this fact Native Hawaiian are trapped in this sort of two worlds one due to tourism which gave rise to high living costs in Hawaii and ruined the traditional indigenous life-style. Hawaiian cannot live as they lived in pre-tourism period, but also they cannot meet new life standards. Haunt Kay talks about how Hawaiian fill up the unemployment lines, and if they want to survive they either enter the military, work in the tourist industry, or leave Hawaii not by choice but out of economic necessity. It is absolutely horrendous that the people of Hawaii working in the tourist industry make a yearly salary of $10,000 to $25,000 which is barely enough for them to live in their own homeland it is sad but true. Looking at the figure that is the low income wage here in the United States, low income individuals still get some kind of help from the government in the united states which helps a little but for the case of the Hawaiian it is different. Why do we think we have so many crime, suicides rates, poverty etc because we are business indeed that we use resources even if it does not belong to us to profit from it. It can be either exploiting ones culture or fighting with other countries so that we can get their resources egg oil. It amazes me what is happening to sacred culture today, we all see ourselves living in this westernizes civilization I ask this question: Do people even care about history? About tradition? About the land we live on? Clearly not for us economy, and cultural impact. Instead of solving one problem we create another. Again rich, power and authority plays a role. To some of us culture is what defines us s individuals our beliefs, traditions are what keeps us at ease, prospers us, we learn to depend on ourselves and Mother Nature. Lets assume that Hawaii was not taken over by industrialization would they manage to survive? Yes they would, for many years they lived that way depending on their resources they have, united as one community and helping each other. Tracks compares the culture exploitation with prostitution, she emphasizes the femininity of Hawaiian culture are like agencies to the pimps, which makes a prostitute to sell her beauty. The native culture was banned from 1990 and its revival in sass as closely connected to tourist exotic language, costumes and dances turned to the lure for tourists. Track declares that communication of hula dancers were made smutty and salacious rather than powerfully erotic as they once were and today the word aloha that meaner the familial love to people and land now becomes almost meaningless because it is often used and has lost its uniqueness and value. Most culture see the exploitation and those are the once are easily taken advantage off, most off which the high chair have the say and the low chair have to suffer for it. Drubbers One World under Business describes how democratic ideals are used to spread capitalism across the world, which he calls corporate. He says how in a robust democracy, there is a firewall between government and business. The firewall ensures that people rather than business control the government and make the rules (Drabber, 429). However, in our democracy, governments interest lies in protecting profits, while corporations use the language of social responsibility to mask their undemocratic actions. While corporat e elites are part of that exclusive club that we envy. Corporations do it in reverse by using democratic language instead of profit-maximizing language to mask undemocratic behavior. Also, countries with very low GAP have no choice but to trade their political power for economic growth and as Friedman said, your political choices Get reduced to Pepsi and Coke (Drabber, 433). We have less political power and corporations have more political power and in order for us to accept that, we hold onto having economic power or democracy (which we do not really have) and corporations claim to show social accountability. This allows corporation to define their own rules, such as aging free trade interchangeable with deregulation, which does not help poorer countries grow, but makes them weaker. Also, these large corporations become huge moneymaking monopolies, Just as the mainstream products we have within our country. Surprisingly in todays democratic society, we rest on the ideal of individualism and freedom. We are supposed to have the freedom to vote, freedom to buy (as consumers), and freedom to choose, all of which are own personal, individual choices with no influence by or reliance on others, that is where the major contradiction in our society lies. Although we think we are individualistic and have freedom, but we do not realize that we are extremely dependent on others for our livelihoods and that only have freedom from traditional and formal institutional structures, but not other freedoms, such as psychological freedom, social and under lets us be indifferent to the suffering that our type of society causes others and ourselves and as a result we feel less accountable to it. Drabber discuss the contradictions of individualism and the bi-polar nature of freedom through publicity and corporate, respectively, and how it affects us socially, politically and economically. Furthermore, Just as consumers, corporations through free market and individualistic ideas do not feel accountable to the people that they depend on their workers and the peripheral countries they rely on for raw materials (also, additional workers and consumers). Drabber described this as uncoupling, which is when the corporation removes itself from the interest of the nation or citizens of a nation. They claim equal loyalty to all nations, once again cushioning it in democratic language. Also, it forces developing nations to be entrapped further in the corporation world and transfer their political power into power as a consumer, exulting in governments who are not able to be accountable to their own people because they are restricted by corporations and global financial market institutions (MIFF, WTFO, etc. . Through the abuses of the poorer people in these developing countries, the powers we have in our own countries are undermined. Although corporations would like for us to believe that we have an economic democracy or economic choices, we do not because we cannot regulate our own economic system that basically tells us what we want. As Drabber says, Real democracy is one person, one vote. One dollar, one vote, is the logic of the market, but it is opposite of the equal representation of all citizens that democracy is about. As a sovereign principle, one dollar, one vote, is inherently undemocratic, and it ensures a growing gap between rich and poor because it gives the rich far more political representation ( 439). These rich corporations have a lot more money than most of us and in result have a lot more political and social say in our market democracy. (Rich, Power and authority) also, in this market democracy, those who do not have any money have no a say at all. Countries look at our society as The Free World because the lack the economies and capital to buy all the stuff we have (the ability to choose products). In our society, with the poor and now even the middle- class, it is becoming more difficult to buy the necessities we need, even though we can see the things we would like to have through advertising. More and more, people have to choose between food, shelter, medication, health insurance and other needs. Still, corporations do not care as long as the consumers buy their products and consumers still try to buy it, even if they do not have the money for it (get loans, credit cards, etc. ). In the end, corporations get their money and often more money Han the products were actually worth. As we see that these articles supplement each other because they describe the same phenomena; Globalization, Lovely Hula hands shows impact of globalization on a person or group of people(Hawaiian) meanwhile one world under business describes the influence of globalization into the whole society. Both articles have an outstanding or rather interesting facts which I would agree that these facts take place everyday in our day to day society. Having said this they share an outstanding sociological significance because they concern to the different branches of sociology.

Communication in Health & Social Care Essay Example | Topics and Well Written Essays - 1000 words

Communication in Health & Social Care - Essay Example This paper will look at communication in the health and social care area and the factor that affect communication in this sector. Factors that affect communication in health and social care area include beliefs and values. Service providers should embrace cultural diversity in order to be able to offer services. If the care giver is not aware of cultural diversity, it is impossible to communicate effectively. Care givers should be competent in the knowledge of culture. This is because people in every culture have their beliefs and values. In a place where there is multiculturalism it may be difficult to communicate (Dickson, Hargie & Morrow, 1996). This calls for care givers to be well informed when it comes to the culture of people they are serving. People perception and understanding of heath and heath care process is developed through their culture and social values. Peoples’ thinking on health and social care is based on their beliefs and values. In the United States health and social care providers are socialized into the culture of their profession. They are trained in the western scientific or bi omedical global view (Argyle, 1994). This teaches the professionals to hold and accept beliefs, norms, and values. This is good because the care givers who know their culture can also appreciate other people’s culture. The more a care giver knows of their culture the more they can accept the patients’ world view. Beliefs of people can affect their compliance with treatment, thus a health care giver should always be able to understand the beliefs of a patient for the service provided to be useful. The care giver should respect the patients’ beliefs and not dismiss their traditional practices. Some beliefs can make a patient lose trust on the care provider thus losing cooperation needed for successful healing and therapeutic relationship. For example, beliefs on herbal medicine may make a