Different reactions Essay Example for Free

Different reactions Essay How quickly a reaction happens is called the rate of reaction. Chemical reactions take place when two or more chemicals react with one another by colliding with each other. The increase in temperature increases the amount of collisions between particles, this fastens the reaction. If a reaction has a low rate that means the molecules combine at a slower speed than a reaction with a high rate. Particles need a minimum amount of kinetic movement if they are going to react when they collide. This is known as Activation energy. The collision theory is the idea that different reactions happen at different rates. Reactions that occur slowly have a lower rate of reaction. Fast reactions are due to an increase of collisions; slow reactions are due to decrease in collisions. Reactions that happen quickly have a high rate of reaction (e. g. explosions). Concentration: The concentration of a solution is how strong the solution is. A stronger acid contains more acid particles and less water particles than a weaker acid. Increasing the concentration of a solution leads to more collisions (greater frequency of collisions) so the rate of the reaction goes up. With a more concentrated acid, the number of acid particles is greater, so the number of collisions is greater and the rate of the reaction is higher (faster. ) Changing the concentration of the acid does not change how quickly the particles are moving (i. e. it doesnt increase the amount of energy they have. ) Temperature: When we increase the temperature at which a reaction is taking place, the particles move more quickly. At a lower temperature, the number of collisions is lower because the particles are moving more slowly. Also when a collision occurs, there is less chance of a reaction taking place because the movement energy in the particles is less. At a higher temperature, the number of collisions is greater because the particles are moving more quickly. When a collision occurs, there is more chance of a reaction taking place because the movement energy in the particles is greater. Gas pressure: Pressure affects the rate of reaction, especially when you look at gases. When you increase the pressure, the molecules have less space in which they can move. That greater concentration of molecules increases the number of collisions. When you decrease the pressure, molecules dont hit each other as often. The lower pressure decreases the rate of reaction. (2) Catalyst: Different catalysts speed up different reactions. The table shows some common catalysts: A catalyst provides a surface on which the reaction can take place. This increases the number of collisions between the particles of the substances that are reacting. A catalyst lowers the activation energy (the minimum amount of energy needed for a reaction to take place). This means that the particles can react with less energy than they needed before the catalyst was added. (3) Surface area of particles: By increasing the surface area of the reactants, there are a higher number of reaction sites. Reaction sites are specific sites on molecules at which reactions occur. Increasing the number of reaction sites increases the number of total collisions. The greater the frequency of total collisions, the greater the frequency of e.ffective collisions. If the frequency of effective collisions increases, so does the reaction rate. Introduction/Aim. In this investigation, I am finding out how concentration affects the rate of reaction between Hydrochloric acid and Sodium Thiosulphate. I am going to measure the rate of reaction when hydrochloric acid is added to sodium thiosulfate. When sodium thiosulfate and Hydrochloric Acid are mixed, a yellow precipitate of sulphur is produced. The solution becomes increasingly difficult to see through as more and more sulphur is formed. This is how I plan to measure the rate of reaction. I will place a paper with a black cross underneath the solution and will stop the clock when the cross can no longer be seen. I will find out the answer by doing a preliminary test to experiment this, I will then compare and discuss the results in my evaluation then I will also state how this experiment I done could be improved, in my conclusion. But before doing the real experiment I will carry out a preliminary test. What is a Preliminary test? This is a test that is done before the real test. It gives an idea of the real thing; through the test you can make changes to make sure the real one is fair and reliable e. g. changing equipment or concentration of sodium thiosulfate solution. A preliminary test is more of a trial than an experiment – to find out if the equipment/method or even experiment works. A preliminary test is generally a baseline for further testing and development. It helps you refine ideas and change key concepts of the experiment. Prediction: Knowing the information above, I predict that as the concentration of the Sodium Thiosulphate increases, the rate of reaction will also increase. This means that the rate/concentration graph I compile from my experiments results will have a positive correlation. I believe this will happen because, according to the collision theory, as the concentration of a solution is increased the number of particles inside the solution increases. If the number of particles inside the solution is increased it makes collisions with reacting particles more likely. Also, I believe that the time/concentration graph will have a negative correlation because if my prediction is true, as the concentration increases the time taken for the reaction to take place will decrease. Preliminary Experiment: I did a preliminary experiment to get used to the sequence of events. I got to know all the apparatus and the method. Word Equation for the reaction: Sodium Thiosulfate + Hydrochloric acid Sodium Chloride + Sulphur + sulphur dioxide + water Ionic equation for reaction: 2Na+ + S2O32- + 2H+ + 2Cl- 2Na+ + 2Cl- + SO2 (g) + S + H2O (l) Balanced Symbol Equation for the reaction: Products Reactants Na2S203 (aq) + 2HCl (aq) 2NaCl (aq) + S (s) +SO2 (g) +H20 (l) I only did the experiment one, not three times so I did not get an average time for each concentration. I made sure the volume of Sodium Thiosulfate solution each time equalled to 10cm3 . The one thing I kept consistent was 10cm3 of Hydrochloric acid. I varied the concentration of the Sodium Thiosulfate and water. Below is a results table for my preliminary experiment. Preliminary Table Volume of water (cm3) Volume of Sodium Thiosulfate (cm3) Concentration (M) Volume of Hydrochloric Acid (cm3) Concentration (M) Time taken (seconds)Â   Preliminary method: 1. If you have not already done so, put on your goggles and gloves. 2. Place the paper with an X onto a flat surface and put a conical flask on top. 3. Measure 9 cm3 of sodium thiosulphate using a pipette and put it into a flask. Then measure 1 cm3 of water using a different pipet. 4. Then measure 10 cm3 of hydrochloric acid using a measuring cylinder. 5. Add first the acid then water and place a ball of cotton wool on top of the flask to block the formed gas from getting into the air. When acid and water is added, immediately start the timer. 6. Look down at the cross from above the flask. When the cross disappears, stop the timer and note the time, recording it in the table. 7. Repeat this process using different concentrations of sodium thiosulpahte solution with water as shown in the table above. 8. Carefully pour the solution into the sink straight after each test. Preliminary Safety: Safety is a key aspect to any experiment. There are a lot of safety issues we must abide when performing this experiment. A key safety aspect was that we covered the top of the conical flask with cotton wool, making sure no gas escapes the air we breathe into as sulphur dioxide; one of the products formed from the experiment is a toxic gas. I also decided to wear goggles to protect my eyes from the acid splashing, squirting or any way entering my eye. Also be sure to tie hair back because if the sodium thiosulphate makes contact with my hair it could dye it blonde (bleach it) or if it comes into contact with my skin it would turn white and peel off. Another precaution to take measure of is wearing gloves to protect your skin as hydrochloric acid is corrosive. Afterwards, when you have done your experiment thoroughly wash away all apparatus used and pour the solution down the sink. Apparatus: 1. Sodium Thiosulphate solution – (This is the variable factor being studied in the reaction) 1. Hydrochloric Acid 2. Water 3. Conical Flask – (to put both the hydrochloric acid and sodium thiosulphate into. ) 4. 3 Pipettes – (one for the hydrochloric acid and one for the sodium thiosulphate and one for water; this allows you to easily transfer the liquids. ) 5. Cotton – (this blocks the top of the conical flask to make sure sulphur dioxide the toxic gas produced doesn’t escape. ) 6. A paper marked with an x – (to be certain when to stop the timer. ) 7. Stop watch/Timer – (to stop the time when ‘X’ is not visible. ) 8. Goggles – (to protect your eyes from acid entering the eyes – for safety measurements. ) 9. Gloves – (protects your skin from hydrochloric acid; corrosive. ) 10. 2 Measuring cylinders’ (to measure the volume of the acids. ) Prediction: I predict that the greater the concentration of Sodium Thiosulfate Solution, the faster the chemical reaction will take place. Therefore, the cross will disappear more quickly due to the cloudiness of the solution. If solutions of reacting particles are made to be more concentrated, there are a higher number of particles reacting. Meaning collisions between Hydrochloric Acid and Sodium Thiosulfate Solution are more likely to occur. All this can be justified by the full understanding of the collision theory itself: For a reaction to occur particles have to collide with each other. Only a small per cent result in a reaction. This is due to the energy barrier to overcome. Only particles with enough energy to overcome the barrier will react after colliding. The minimum energy that a particle must have to overcome the barrier is called the activation energy, or Ea.

Corruption in Ken Keseys One Flew Over the Cuckoos Nest :: One Flew Over Cuckoos Nest

Corruption in One Flew Over The Cuckoo's Nest As Lord Acton put it in a letter to Bishop Mandell Creighton, "Power tends to corrupt, and absolute power corrupts absolutely. Great men are almost always bad men." This is the truth that is evident both in Ken Kesey book One Flew Over The Cuckoo's Nest. His main characters Nurse Ratched and Randal McMurphy are in a subtle underground war against each other's accumulating power, and corruptness. This idea of great men being bad men is evident in Kesey's book, my experiences, and society in general. Ken Kesey appears to show disgust for people of power in his book One Flew Over The Cuckoo's Nest. Throughout the novel, Nurse Ratched, the lady within whom lays all the power of the staff in a mental institution, frequently sends people who she has behavioral problems with off to the disturbed wing, like she did Maxwell Taber. It is there that they experience the pain of either electroshock therapy, or a full frontal lobotomy. Nurse Ratched uses this and her natural dominance to inspire fear in her patients. She tends to agree with old school of thought that a healthy dose of fear makes people easier to control. Thus she was able to easily putdown any uprising against her totalitarian rule before Randle McMurphy. Nurse Ratched tries to use the power that has been given to her as head nurse to change the patients as she sees fit. As Bromden puts it, "Working alongside others... she is a veteran of adjusting things" (p. 30). But to do this she has created a living hell for them. McMurphy, one of the rare man that dares to vocalize his opinion, shows his negative sentiment towards Nurse Ratched when he tells Harding, "Hell with that; she's a bitch a ball cutter..." (p. 58). The entire ward can see how power has corrupted Nurse Ratched into the pseudo-megalomaniac/sadist she now is. I agree with Kesey's view of power. I once had a teacher who would grade harder for people he didn't like. As a result if he disliked one of his students, they were guaranteed a `C' or lower. His abuse of power went unchecked and unchallenged due to his seniority and the difficulty of proving his crime.

Conclusion on Poem in the Bazaar of Hyderabad Essay

Summary: It is a beautiful poem written by Sarojini Naidu. She has used good language and fluent English which is quite surprising as she is an Indian poetess. She has described the beauty of a traditional Indian market or â€Å"bazaar†. She has touched upon all five senses. We can hear the music produced by our traditional Indian musical instruments played by the musicians and the chantings of the magicians. Delicious fruits like citron, pomegranate and plum are being sold by the fruit-men, while the vendors are weighing saffron, lentil and rice (Indian staple food). The pleasant fragrance of sandalwood an henna can be smelt. Also the smell of flowers which are woven into chaplets and garlands is in the air. One can see the richness of wares in the bazaar. The poetess has metiond colours such as crimson, purple, silver, amber, azure and red. The shows what all goods are sold in an Indian bazaar. Turbans of crimson and silver, tunics of purple brocade, , mirrors with panels of amber, daggers with handle of jade, chessmen, ivor dice, anklets, wristlets, rings, bels for the fet of blue pigeons, girdles of gold, and scabbards for the king are all examples of the expensive wares sold in the bazaars of Hyderabad. Message: First of all, one must know that this poem was written during the freedom struggle of India, So Sarojini Naidu has been trying to unite the Indians to drive the British out of India. She is trying to encourage the Indians to buy goods from their traditiona bazaars rather than purchasing foreign goods. She is telling her country men to take part in Gandhiji’s Swadeshi movement and boycott all British goods. At that time the publication of Indian newspapers were banned, so writing a poem was the best way to spread this message.

Biography of Edmonia Lewis, American Sculptor

Edmonia Lewis (c. July 4, 1844–September 17, 1907) was an American sculptor of African-American and Native American heritage. Her work, which features themes of freedom and abolition, became popular after the Civil War and earned her numerous accolades. Lewis depicted African, African-American, and Native American people in her work, and she is particularly recognized for her naturalism within the neoclassical genre. Fast Facts: Edmonia Lewis Known For: Lewis was a sculptor who used neoclassical elements to depict African-American and Native American people.Born:  July 4 or July 14, in either 1843 or 1845, possibly in upstate New YorkDied: September 17, 1907 in London, EnglandOccupation: Artist (sculptor)Education: Oberlin CollegeNotable Works:  Forever Free  (1867),  Hagar  in the Wilderness  (1868),  The Old Arrow Maker and His Daughter  (1872), The Death of  Cleopatra  (1875)Notable Quote: I was practically driven to Rome in order to obtain the opportunities for art culture, and to find a social atmosphere where I was not constantly reminded of my color. The land of liberty had not room for a colored sculptor. Early Life Edmonia Lewis was one of two children born to a mother of Native American and African-American heritage.  Her father, an African Haitian, was a gentlemens servant. Her birthdate and birthplace (possibly New York or Ohio) are in doubt. Lewis may have been born on July 14 or July 4, in either 1843 or 1845. She herself claimed her birthplace was upstate New York.   Lewis spent her early childhood with her mothers people, the Mississauga band of Ojibway (Chippewa Indians). She was known as Wildfire, and her brother was called Sunrise. After they were orphaned when Lewis was about 10 years old, two aunts took them in. They lived near Niagara Falls in northern New York. Education Sunrise, with wealth from the California Gold Rush and from working as a barber in Montana, financed his sisters education that included prep school and Oberlin College. She studied art at Oberlin beginning in 1859. Oberlin was one of very few schools at the time to admit either women or people of color. Lewiss time there, though, was not without its difficulties. In 1862, two white girls at Oberlin accused her of attempting to poison them. Lewis was acquitted of the charges but was subjected to verbal attacks and a beating by anti-abolitionist vigilantes. Even though Lewis was not convicted in the incident, Oberlins administration refused to allow her to enroll the next year to complete her graduation requirements. Early Success in New York After leaving Oberlin, Lewis went to Boston and  New York to study with sculptor Edward Brackett, who was introduced to her by abolitionist William Lloyd Garrison. Soon, abolitionists began to publicize her work.  Lewiss first bust was of Colonel Robert Gould Shaw, a white Bostonian who led black troops in the Civil War. She sold copies of the bust, and with the proceeds she was eventually able to move to Rome, Italy. Move to Marble and Neoclassical Style In Rome, Lewis joined a large artistic community that included other women sculptors such as Harriet Hosmer, Anne Whitney, and Emma Stebbins. She began to work in marble and adopted the neoclassical style, which included elements of ancient Greek and Roman art. Concerned with racist assumptions that she wasnt really responsible for her work, Lewis worked alone and was not part of the community that drew buyers to Rome. Among her patrons in America was abolitionist and feminist Lydia Maria Child. Lewis converted to Roman Catholicism during her time in Italy. Lewis told a friend that she lived within the city of Rome to support her art: There is nothing so beautiful as the free forest. To catch a fish when you are hungry, cut the boughs of a tree, make a fire to roast it, and eat it in the open air, is the greatest of all luxuries. I would not stay a week pent up in cities, if it were not for my passion for art. Edmonia Lewis most famous sculpture: The Death of Cleopatra (1876). Wikimedia Commons/Public Domain Famous Sculptures Lewis had some success, especially among American tourists, for her depictions of African, African-American, and Native American people. Egyptian themes were, at the time, considered representations of Black Africa. Her work has been criticized for the Caucasian look of many of her female figures, though their costuming is considered more ethnically accurate. Among her best-known sculptures are Forever Free (1867), a sculpture commemorating the ratification of the 13th Amendment and which depicts a black man and woman celebrating the Emancipation Proclamation; Hagar in the Wildnerness, a sculpture of the Egyptian handmaiden of Sarah and Abraham, mother of Ishmael; The Old Arrow-Maker and His Daughter, a scene of Native Americans; and The Death of Cleopatra, a depiction of the Egyptian queen. Lewis created the The Death of Cleopatra for the 1876 Philadelphia Centenniel, and it was also displayed at the 1878 Chicago Exposition. The sculpture was lost for a century. It turned out to have been displayed on the grave of a race track owners favorite horse, Cleopatra, while the track was transformed first into a golf course and then a munitions plant. With another building project, the statue was moved and then rediscovered, and in 1987 it was restored. It is now part of the collection of the Smithsonian American Art Museum. Death Lewis disappeared from public view in the late 1880s. Her last known sculpture was completed in 1883, and Frederick Douglass met with her in Rome in 1887. A Catholic magazine reported on her in 1909 and there was a report of her in Rome in 1911. For a long time, no definitive death date was known for Edmonia Lewis. In 2011, cultural historian Marilyn Richardson uncovered evidence from British records that she was living in the Hammersmith area of London and died in the Hammersmith Borough Infirmary on September 17, 1907, despite those reports of her in 1909 and 1911. Legacy Though she received some attention in her lifetime, Lewis and her innovations were not widely recognized until after her death. Her work has been featured in several posthumous exhibitions; some of her most famous pieces now reside in the Smithsonian American Art Museum, the Metropolitan Museum of Art, and the Cleveland Museum of Art. Sources Atkins, Jeannine.  Stone Mirrors: The Sculpture and Silence of Edmonia Lewis.  Simon Schuster, 2017.Buick, Kirsten.  Child of the Fire: Mary Edmonia Lewis and the Problem of Art History’s Black and Indian Subject.  Duke University Press, 2009.Henderson, Albert.  The Indomitable Spirit of Edmonia Lewis: A Narrative Biography.  Esquiline Hill Press, 2013.