Alexandria

Alexandria Alexandria. 1 City (1990 pop. 49,188), seat of Rapides parish, central La., on the Red River; inc. 1818. It is a trade, rail, and medical center for a rich agricultural and timber area. Among its many manufactures are fabricated metals, wood panels, adhesives, and fishing lures. During the Civil War the city was burned (May, 1864) by federal troops. Alexandria is the headquarters for Kisatchie National Forest and the seat of a branch of Louisiana State Univ. Louisiana College is in the neighboring twin city of Pineville. 2 City (1990 pop. 111,183), independent and in no county, N Va., a port of entry on the Potomac; patented 1657, permanently settled 1730s, inc. 1779. Primarily a residential suburb of Washington, D.C., it also has extensive railroad yards and repair shops, a deepwater port, and varied industry (printing and publishing, fiber optics research, and machinery and computer-hardware manufacturing). A number of U.S. government buildings and scientific and engineering r esearch firms are there; Crystal City and Pentagon City are vast office developments. George Washington helped lay out the streets in 1749. The city was part of the District of Columbia from 1789 to 1846. In May, 1861, it was occupied by federal troops; it was cut off from the rest of the South throughout the Civil War. Its many historic buildings include Gadsby's Tavern (1752), frequented by Washington; Carlyle House (1752), where Washington received his commission as major; Christ Church (1767â€"73), where Washington, and later Robert E. Lee, worshiped; and Ramsey House (1749â€"51). The George Washington Masonic National Memorial Temple (1923â€"32), modeled after the ancient lighthouse at Alexandria, Egypt, houses Washington mementos. The Alexandria Gazette, among the nation's oldest daily newspapers, was first printed in 1784. Nearby are Mount Vernon ; Woodlawn, one of the Washington family estates; an Episcopal seminary (1823); Fort Belvoir; and the U.S. Army Engineer Center, with an engineering school and research and development laboratories. The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved. See more Encyclopedia articles on: U.S. Political Geography

Cry the Beloved Country dialectical journal - 1678 Words

Cry, the Beloved Country Dialectical Journals Theme: Racial Inequality Injustice Quote Response â€Å"Kumalo climbed into the carriage for non-Europeans, already full of the humbler people of his race†¦Ã¢â‚¬  (43) How there’s a carriage exclusively for non-Europeans is understandable at the time period that this novel is set in, but people who read this in the 21st century might think that this is odd how Europeans couldn’t stand to ride in the same carriage as non-Europeans. â€Å"Black and white it says, black and white, though it is red and green. It is too much to understand.† (47) The order it goes, black and white then red and green. It shows you that the whites are more superior because they are the sign to go, and the blacks have to stop and†¦show more content†¦And being in a foreign place makes it even more confusing on if you should trust anyone or not. When you’re poor like Kumalo was, money was very precious to you. He was taking money that was going to be used for clothes. Seeing someone run off with your money is something that makes you lose faith in the human race. Cry, the Beloved Country Dialectical Journals Theme: Economic Prosperity v. Loss of Values Quote Response â€Å"She came here to look for her husband who was recruited for the mines†¦ She lives in Claremont, not far from here. It is one of the worst places in Johannesburg†¦ †¦ that is her work, she makes and sells it†¦ These women sleep with any man for their price†¦ She has been in prison, more than once.† (53) Kumalo’s sister went to the big city to find her husband and it turns out that she never did. At least that’s what it seems like it’s trying to hint at. It seems like as soon as she entered a place to be rumored as a better economic area, she lost all morals and values. This is sad really, for both Kumalo and his sister. (55) Cry, the Beloved Country Dialectical Journals Theme: Poverty Quote Response â€Å"How can I use it? he said. This money was to send Absalom to St. Chad’s†¦ This money we have saved for that purpose will never be used for it.† (38-39) Stephen feels if he were to use the money they saved for his son it wouldn’t be right. He also knows that ifShow MoreRelatedCry, The Beloved Country Journal1487 Words   |  6 Pages Jeffrey Dao Ms. Hastings Period 1 October 7, 2014 Cry, the Beloved Country Journal Table of Content Topic Page Number Focus on Conflict Responses 2 Focus on Theme Responses 3-5 SAR Responses Chapter Questions Responses Dialectical Journals Works Cited  Focus on Conflict In book 1 of Cry, the Beloved Country, the main conflict was Kumalo’s loss of faith. In this quote,â€Å"But that he should kill a man, a white man! There was nothing that he could remember, nothing, nothing at all, that couldRead MoreOrgan Donation1872 Words   |  8 Pagestransplants because of the shortage of donated organs (Medline Plus). The detrimental outcome upon U.S. citizens due to low organ donation is immense compared to that of Austria, France and Spain. Austria has the shortest organ waiting list of the world’s countries, with twenty-nine donors per one million inhabitants, whereas America has six donors per one million inhabitants (Donate Life America). These severe statistics prompt the question, why is the rate of organ donation in the United States, seeminglyRead Morewisdom,humor and faith19596 Words   |  79 Pagesâ€Å"people are wise to the extent that they use their intelligence to seek a common good. They do so by balancing, in their course s of action, their own interests with those of others and those of larger entities, like their school, their community, their country, even God.† In fostering wisdom, Sternberg also thinks it is important to teach people to see â€Å"things from others’ perspectives as well as one’s own,† to tolerate â€Å"other people’s points of view, whether or not one agrees with such views.† He refers

Essay on American Pie. Coercive Sexuality - 693 Words

Coercive Sexuality By Diep Chu FS 337 March 2013 Coercive Sexuality Coercive sexuality is an important factor in American Pie movie. In this movie, audiences can see different pictures of teenagers trying to experiences sexual intercourse for the first time in their lives (Zide, Perry, and Weitz, 1999). And the more aggressive they are, people can see coercive sexuality involved in different scenes. Coercive sexual behavior among students has been an area of concern to society. At the time when human sexuality topic becomes so popular in teenagers’ world, those students in the movies let people understand more about their points of views about sexuality. The question that I want to address in this paper is: Do we as a†¦show more content†¦But on her side, she sure will not be happy to have him do that without her consent (Zide, Perry, and Weitz, 1999). In what way do the attitudes towards these mirrors the attitudes of our society in general? For many years society tried to control sexual behavior in youth by citin g the traditional negative consequences of sexual experiences and community disapproval. Television, being the highly influential, has been both part of the solution and part of the problem in the area of sex and youth. At the beginning, Jim was watching porn and his parents notice it (Zide, Perry, and Weitz, 1999). This would happen to many families in our society today when kids are in puberty. Those entertainments affect teen’s sexual behavior heavily. They will copy those disapproval contents in it. At almost the end of the movie, those youth figured out they want to experience sex only because of peer pressure. They finally understand sex had no meaning without love or the girls’ willingness (Zide, Perry, and Weitz, 1999). Public education has had some major problems in this area and few schools have any real programs in sex education. Many parents do not want their children to learn about sex early. But the more they avoid it, the more kids want to learn about it . This movie indicates good pictures of how teens nowadays think about sex. The sexual values are much different in themShow MoreRelatedLeading Function of Management15642 Words   |  63 Pages16 ORGANIZATION AND MANAGEMENT – Report on The LEADING Function of Management 7) Contributions of Elton Mayo : The work of Elton Mayo is famously known as â€Å"Hawthorne Experiments.† He conducted behavioral experiments at the Hawthorne Works of the American Western Electric Company in Chicago. He made some illumination experiments, introduced breaks in between the work performance and also introduced refreshments during the pause’s. On the basis of this he drew the conclusions that motivation was aRead MoreOne Significant Change That Has Occurred in the World Between 1900 and 2005. Explain the Impact This Change Has Made on Our Lives and Why It Is an Important Change.163893 Words   |  656 Pagesand Paul Buhle, eds., The New Left Revisited David M. Scobey, Empire City: The Making and Meaning of the New York City Landscape Gerda Lerner, Fireweed: A Political Autobiography Allida M. Black, ed., Modern American Queer History Eric Sandweiss, St. Louis: The Evolution of an American Urban Landscape Sam Wineburg, Historical Thinking and Other Unnatural Acts: Charting the Future of Teaching the Past Sharon Hartman Strom, Political Woman: Florence Luscomb and the Legacy of Radical Reform

Ester Hydrolysis Free Essays

The Equilibrium Constant of an Ester Hydrolysis Reaction Abstract: The results from this experiment show four different Kc equilibrium constants of: . 1522 for bottle two, . 1853 for bottle three, . We will write a custom essay sample on Ester Hydrolysis or any similar topic only for you Order Now 2094 for bottle four, and . 2678 for bottle five. The average Kc value came out to be . 2037 for all four bottles. Purpose: The purpose of this lab is to determine the equilibrium concentrations of an organic acid, an alcohol, an ester, and water in four bottles with varying measurements of each compound in of the four solutions. Once the concentrations are determined, one is then to discover the Kc, equilibrium constant, of those solutions by dividing the concentrations of alcohol and acid by the concentrations of ester and water. Methods/Procedure: First begin by mixing up and standardizing a 500mL solution of NaOH to titrate. For each of the six bottles, measure the directed amounts of ester, water, alcohol, and HCl. The bottles of different solutions will be left to come to equilibrium for two weeks. Once the NaOH is standardized, the solutions in the bottles have come to equilibrium, and a molarity is calculated, use the molarity of NaOH to discover how many mols were used to neutralize the solutions in each bottle. Once all of the calculations are complete, use an ICE chart to discover the mols of ester, water, acid, and alcohol at equilibrium to then calculate the Kc for each bottle. After a Kc has been calculated for all bottles, the last step is to determine an average Kc for all of the solutions. Calculations/Results: Grams of KHP needed: 7mol x 35ml x 1molKHP x 204gKHP1000ml x 1 x 1molNaOH x 1molKHP=5. 00gKHP Grams of NaOH: .7molNaOH x . 500L x 1mol 1L x 1 x 40g~14gNaOH Mass of dish: 1. 80g Mass of bottle 1: 17. 1145g Mass of HCl 1: 4. 8778g Mass of NaOH 14. 0g Mass of bottle 1A: 17. 3521g Mass of HCl 1A: 5. 2319g Mass of dish: 2. 0097g Mass of dish and KHP: 6. 0548g Mass of KHP: 5. 0378g mL of NaOH used to neutralize KHP: 1. 36. 90mL 2. 30. 80mL 3. 36. 40mL g of KHP: 1. 5 . 0378g 2. 4. 2074g 3. 4. 9722g Molarity of NaOH: .6690M| 6689M| Avg M: . 6688M NaOH| 5. 0378gKHP x 1molKHP x 1molNaOH x 1 x 1000mL1 x 204. 2g x 1molKHP x 36. 90mL x 1L=. 6686M mL of NaOH used: 1A: 6. 20mL – 24. 90mL = 18. 70mL| 1: 17. 00mL| 2: 60. 54mL| 3: 58. 60mL| 4: 45. 55mL| 5: 40. 75mL| Ethanol: Water:Ethyl Acetate: Density: . 7893g/mL Density: . 9982g/mLDensity: . 9003g/mL Molar Mass: 46. 07g/molMolar Mass: 18. 02g/molMolar Mass: 88. 11g/mol mL of solutions in each bottle: Bottle #| 3M HCl (mL)| H2O (mL)| Ester (mL)| Alcohol (mL)| 1| 5. 00| 5. 00| 0| 0| 1A| 5. 00| 5. 00| 0| 0| 2| 5. 00| 0| 5. 00| 0| 3| 5. 00| 1. 00| 4. 00| 0| 4| 5. 0| 3. 00| 2. 20| 0| 5| 5. 00| 2. 00| 2. 00| 1. 00| Bottles 1 and 1A M HCl: 17. 00mLNaOH x . 6688molNaOH x 1 molHCl x 11 x 1000ml x 1molNaOH x . 005LHCl=2. 27MHCL x . 005L= . 01137molHCl .01251 molHCl Average mol HCl of bottles 1 and 1A: (. 01251mol + . 01137mol)/2 = . 01194molHCl Mol NaOH for bottles 2-5: .6688MNaOH x 1L x 60. 54mLNaOH1L x 1 000mL x 1= . 04049molNaOH .03919molNaOH .03046molNaOH .02725molNaOH Density of HCl: 5. 2319gHCl x 11 x 5. 00mL=1. 046g/mLHCl Grams of HCl and H2O: 1. 046gHCl x 5. 00mLH2O1mL=5. 230gHCl+H20 Grams of HCl: .01194molHCl x 36. 54gHCl1 mol HCl= . 4352gHCl Grams of HCl and H2O – Grams of HCl: 5. 230gHCl+H2O – . 4352gHCl = 4. 794gH2O from 5. 00mL of HCl in bottles 1-5 Grams of H2O made + grams H2O given for bottles 2-5: 4. 794gH2O + 0. 00mLH2O x . 9982gH2O/mL = 4. 794gH2O 5. 792gH2O 7. 789gH2O 6. 790gH2O Grams to mols of H2O for bottles 2-5: 4. 794gH2O x 1molH2O1 x 18. 02gH2O= . 2661molH2O .3214molH2O .4322molH2O .3768molH2O Mols of ester for bottles 2-5: 5. 00mLester x . 9003gester x 1mol ester1 x 1mL x 88. 11gester= . 05109mols ester .4087mols ester .02248mols ester .02044mols ester Mols of acid for bottles 2-5: 60. 54mLNaOH x 1L x . 688molNaOH x 1molacid1 x 1000mL x 1L x 1molNaOH x 1= . 04049molacid .03919molacid .03046molacid .02725molacid Total mols of acid – mols HCl for bottles 2-5: .04049mol total acid – . 01194mol HCl = . 02855mol organic acid . 02725mol organic acid . 01852mol organic acid .01531mol organic acid Mols of alcohol for bottle 5: 1. 00mLalcohol x . 7893galcohol x 1 mol alcohol1 x 1mL x 4 6. 07galcohol= . 01713mol alcohol Ice Charts for bottles 2-5: ESTER (mol)| WATER (mol)| ACID (mol)| ALCOHOL (mol)| I: . 05109| . 2661| 0| 0| C: -. 2855| -. 02855| -. 02855| -. 02855| E: . 02254| . 2376| . 02855| . 02855| ESTER (mol)| WATER (mol)| ACID (mol)| ALCOHOL (mol)| I: . 04087| . 3214| 0| 0| C: -. 02725| -. 02725| -. 02725| -. 02725| E: . 01362| . 2942| . 02725| . 02725| ESTER (mol)| WATER (mol)| ACID (mol)| ALCOHOL (mol)| I: . 02248| . 4322| 0| 0| C: -. 01852| -. 01852| -. 01852| -. 01852| E: . 00396| . 4137| . 01852| . 01852| ESTER (mol)| WATER (mol)| ACID (mol)| ALCOHOL (mol)| I: . 02044| . 3768| 0| . 01713| C:-. 01531| -. 01531| -. 01531| . 01531| E: . 00513| . 3615| . 01531| . 03244| Kc for bottles 2-5: Kc=. 02855[. 02855]. 0254[. 376]= . 1522 .1853 .2094 .2678 Avg Kc: .1522 + . 1853 +. 2094 + . 2678 = . 8147 .8147/4 = . 2037 Discussion: A known error in this experiment with this data is the mass of hydrochloric acid measured for bottle 1. The mass was below 5 grams (4. 8778g) which threw the calculations off. To compensate for the poor data, an average of the two masses of hydrochloric acid was taken, and then the number of moles was found to get a better approximation of what the number of moles should be. Another possible error in this experiment was not having adequate time for the solutions to equilibrium completely. If the solutions had not fully reached equilibrium the equilibrium constant would be off for whichever solutions, if not all, that had not come to equilibrium. The Kc values were all approximately one tenth off of each other. In theory, the Kc values should all be the same which indicates that there is a high probability that the solutions had not fully reached equilibrium. In conclusion, the results would have been closer and more exact had the solutions had more time to come to equilibrium as well as if the mass of hydrochloric acid was closer to where it should have been. How to cite Ester Hydrolysis, Papers

Tennis Essay Example For Students

Tennis Essay It was my last year at San Fernando high. It was a memorable time of my lifebecause I knew that I would graduate at the end of that year. My senior yearalso became the most significant year of my life, because I got to do somethingthat I have always wanted to try tennis. I had always wanted to play tennis eversince I was a kid, but there wasnt enough time for me to join tennis team. Oneday, Mr. Cockerill who was my teacher and also the tennis coach, encouraged meto join the team. I thought it might be the only chance for me to get involved,and decided to join the team. Mr. Cockerill was assigned to be our coach. He isa tall, strong old man with a red face. I loved to listen of what he said,because I felt he was giving me a valuable lesson especially during practicehours that he thought it could be use for the game. My first lesson was not thatgreat. I had to pick up the balls most of the time. I was unable to hold firmlya tennis rackets grip. I practiced very hard almost every day af ter schoolincluded the weekends. There were few times I wanted to quit the challenges, butmy friends had given back my courage. These friends of mine had started playingtennis two years before I came in to join the team. Their skills were so muchimproved compared to me. They were willing to stay and practice with me. I wasalso happy that my oldest brother, an excellent singles player helped me out atthe start. At home I often admire his awards and whispered to myself that;I would never get one like this all my life. It is impossible for me to bean athlete. In the beginning, I knew that I wasnt a good player, but itdidnt stop me from joining the team. However my father was worried that if Icame home so late at night, I wouldnt have enough time to study for otherclasses. He didnt allow me to be involved in this kind of activity. I wanted tobeg my dad to let me continue, but we didnt have a good communication with eachother. I felt either very guilty for not joining the team or for goi ng againstmy dads will. He would disown me if I didnt listen to him. I felt I was pushedto the edge of a cliff. His attitude had emotionally hurt when I personallyheard it of what he had treated me. I couldnt stop crying for days. My tearsjust ceaselessly drooped. My coach worried why I didnt look so well in class. We will write a custom essay on Tennis specifically for you for only $16.38 $13.9/page Order now He asked few times, but I couldnt find a way to start explaining the wholesituation. I really wanted to resolve this problem as soon as possible. It wasmy dream to be in tennis team, and Mr. Cockerill was the only person who cantalk to my dad. Finally, he actually did let me join the team. In the end, Irealized that how difficult it was for me to be on the tennis team. I shouldplay my best in order to please my dad, my coach, my friends, and for SanFernando high. During the first tournament, I was very nervous and excited atthe same time. It was my first competition; I couldnt hold my racket still. Myentire body was shaking, but luckily no one noticed that. Mr. Cockerill gatheredus in class and explained what the strategies would be and how we should play. He also reminded us to have a positive attitude even if we lost the game. At theend of the game I lost to my opponent with a scoring 3-8. I felt very happy thatat least I had made some effort for my score, and I took me few weeks topractice. Mr. Cockerill was very kind and so understanding. He didnt only slowanything about the lost, but he also took well care of us with cookies, fruitsand drinks. I had followed his teaching, as long as you all do your best,I am very please, and I ask no more than that. I kept it as anencouragement. My time was devoted to this game at least one or two hourseveryday. Mr. Cockerill was very satisfied because I would never complain aboutthe practice section and I always gave smile at him. I practically never won thegame myself, although I had learned to improve my skill from those experts whohad been playing for years. I didnt feel that bad because it took me a fewmonths to be Varsity. I didnt win any game, but I could tell myself each time Ihad to play that, I have done my best. Once, during a game, Itwisted my ankle when I served the ball. I said nothing to my coach, because Iwas afraid to let him down nor I wanted him to be worried. They didnt realizehow hurt I was at that day. I had to pretend to smile at my team. I was veryqueer; I had to endure that physically pain till the last second. It took me fewdays to recover my ankle. That was also the last game that I played for SanFernando high. The last day of a semester, Mr. Cockerill invited all of membersin the team to the banquet. There most of my team members had received theiraward letters and trophies. At last, the final trophy was given as aninspiration to Kim-Anh Le, he yelled out loud. It is forme? I was so surprise and looked around the room to see if he was kiddingme. I was speechless at that moment. As I walked up to the stage to receive theaward, I heard all the clapping hands toward me. Mr.Cockerill gave me a hug andwhisper in my ear, you deserve it, honey. I am very proud of you.This beautiful day has always been there ever since I graduated. It was such abest memory that I had treasured in my heart. It couldnt describe how myfeeling was at the banquet, but Mr. Cockerill had adhered to my mind, he wasalways there for me to look up to. All I really wanted to say is thanks toMr. Cockerill for giving me a best lesson that I have ever had. Now I haveable to play tennis without any help. .uac2f96291216f0fb9ec7c4c35031cde7 , .uac2f96291216f0fb9ec7c4c35031cde7 .postImageUrl , .uac2f96291216f0fb9ec7c4c35031cde7 .centered-text-area { min-height: 80px; position: relative; } .uac2f96291216f0fb9ec7c4c35031cde7 , .uac2f96291216f0fb9ec7c4c35031cde7:hover , .uac2f96291216f0fb9ec7c4c35031cde7:visited , .uac2f96291216f0fb9ec7c4c35031cde7:active { border:0!important; } .uac2f96291216f0fb9ec7c4c35031cde7 .clearfix:after { content: ""; display: table; clear: both; } .uac2f96291216f0fb9ec7c4c35031cde7 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .uac2f96291216f0fb9ec7c4c35031cde7:active , .uac2f96291216f0fb9ec7c4c35031cde7:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .uac2f96291216f0fb9ec7c4c35031cde7 .centered-text-area { width: 100%; position: relative ; } .uac2f96291216f0fb9ec7c4c35031cde7 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .uac2f96291216f0fb9ec7c4c35031cde7 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .uac2f96291216f0fb9ec7c4c35031cde7 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .uac2f96291216f0fb9ec7c4c35031cde7:hover .ctaButton { background-color: #34495E!important; } .uac2f96291216f0fb9ec7c4c35031cde7 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .uac2f96291216f0fb9ec7c4c35031cde7 .uac2f96291216f0fb9ec7c4c35031cde7-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .uac2f96291216f0fb9ec7c4c35031cde7:after { content: ""; display: block; clear: both; } READ: The Dangers Of Cyber Bullying EssaySports and Games

dertermining the rate equation essays

dertermining the rate equation essays Title: determination of the rate equation Task: Plan design and conduct an experiment to determine the rate equation for the reaction between Sodium Thiosulphate Na2S2O3 and Hydrochloric Acid HCl 2HCl(aq) + Na2S2O3(aq) 2NaCl (aq) + SO2(g) + S(s) + H2O(l) 0.4 mol dm-3 Sodium Thiosulphate Na2S2O3 10cm3, 25cm3, 50cm3 measuring cylinder 1. Measure out 50cm3 of sodium Thiosulphate using the 50cm3 measuring cylinder 2. Pour this into the 100ml conical Flask 3. The conical Flask should be placed on the paper with the x marked clearly on it. 5. add this to 22.5cm3 of distilled water 6. add this dilute mixture of HCl to the sodium Thiosulphate 8. record how long it takes for the cross to disappear 9. carry out the experiment again for the volumes mentioned in the table below (x) Initial Volume of water/ cm3 Initial Concentration of Dilute HCl/ Moles dm-3 Time taken/ Seconds Relative Initial Rate 1/t 0 25 x/ total volume * number of concentrations The concentrations that I have chosen to do vary from those that were done in the experiment because I wanted to see what would happen if I doubled the concentration of HCl and reduced the volume of water used, what affect it would have on the rate. In theory as initial concentration of HCl doubles or quadruples the initial rate should also double or quadruple. The volumes that I have chosen are shown above in the table. The amount of HCl and distilled water used always equals 50cm3 in total as it did in the demonstration. I have chosen o choose eleven different co ...

Rules for Assigning Oxidation Numbers

Rules for Assigning Oxidation Numbers Electrochemical reactions involve the transfer of electrons. Mass and charge are conserved when balancing these reactions, but you need to know which atoms are oxidized and which atoms are reduced during the reaction. Oxidation numbers are used to keep track of how many electrons are lost or gained by each atom. These oxidation numbers are assigned using the following rules. Rules for Assigning Oxidation Numbers The convention is that the cation is written first in a formula, followed by the anion. For example, in NaH, the H is H-; in HCl, the H is H.The oxidation number of a free element is always 0.  The atoms in He and N2, for example, have oxidation numbers of 0.The oxidation number of a monatomic ion equals the charge of the ion.  For example, the oxidation number of Na is 1; the oxidation number of N3- is -3.The usual oxidation number of hydrogen is 1.  The oxidation number of hydrogen is -1 in compounds containing elements that are less ​electronegative than hydrogen, as in CaH2.The oxidation number of oxygen in compounds is usually -2.  Exceptions include OF2 because F is more electronegative than O, and BaO2, due to the structure of the peroxide ion, which is [O-O]2-.The oxidation number of a Group IA element in a compound is 1.The oxidation number of a Group IIA element in a compound is 2.The oxidation number of a Group VIIA element in a compound is -1, except when t hat element is combined with one having a higher electronegativity.  The oxidation number of Cl is -1 in HCl, but the oxidation number of Cl is 1 in HOCl. The sum of the oxidation numbers of all of the atoms in a neutral compound is 0.The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.  For example, the sum of the oxidation numbers for SO42- is -2.