Sodium Thiosulphate Coursework Essay Example for Free

Sodium Thiosulphate Coursework Essay We must produce a piece of coursework investigating the rates of reaction, and the effect different changes have on them. The rate of reaction is the rate of loss of a reactant or the rate of formation of a product during a chemical reaction. It is measured by dividing 1 by the time taken for the reaction to take place. There is five factors which affect the rate of a reaction, according to the collision theory of reacting particles: temperature, concentration (of solution), pressure (in gases), surface are (of solid reactants), and catalysts. I have chosen to investigate the effect temperature and concentration have on a reaction. This is because they are the most practical to investigate it would take longer to prepare a solid in powdered and unpowdered form, and it is difficult to get accurate readings due to the inevitabilities of human errors, and as gas is mostly colourless it is difficult to gauge a reaction changing the pressure, and if a substance is added to give the gas colour, it may influence the outcome of the experiment. Similarly the use of a catalyst complicates things, and if used incorrectly could alter the outcome of the experiment. Experiment 1 Changing the concentration 5 cm3 of HCl (at concentration 1 mol./dm3) and 15 cm3 of sodium thiosulphate (at varying concentrations 10 to 35 g/dm3) are poured out into two measuring cylinders and then poured into a conical flask, which is placed on top of a board marked with letter X. The stopwatch will now be started. When the mixture has turned sufficiently cloudy so that the letter X can no longer be seen the stopwatch will be stopped and the time will be recorded. The experiment is repeated with all the concentrations. The whole procedure is then repeated. Experiment 2 Changing the temperature 5 cm of HCl (at concentration 1 mol./dm3) and 15 cm of sodium thiosulphate (at varying concentrations 10 to 35 g/dm3) are poured out into two measuring cylinders. A beaker is half filled with hot water from a tap. The water is placed on top of a Bunsen on a blue flame and the two measuring placed inside the water bath. The water is heated to the necessary temperature (30?C to 70?C) then the two measuring cylinders are taken out and the contents of both are poured into a conical cylinder. The time it takes for the X to disappear is timed and recorded. The experiment is repeated using all the temperatures. The entire procedure is the repeated. Repeat results and averages will be taken to improve the credibility of the findings, and present solid grounding for the final conclusion. The repeat results will help to iron out any anomalies and the average will give a good summary of the results of the experiment. However if one set of results is entirely different to the other, a third experiment will be performed to replace the anomalous set of results. Safety A pair of goggles will be worn during the heating part of the experiment in order to protect the eyes. An apron will also be worn to protect the skin and clothing. When handling hot beakers and measuring cylinders a pair of tongs will be used. A gauze and heatproof mat will be used while heating to avoid any damage to the equipment. Fair Test In order for my findings to be valid the experiment must be a fair one. I will use the same standard each time for judging when the X has disappeared. I will make sure that the measuring cylinders for the HCl and thiosulphate will not be mixed up. The amount of HCl will be 5 cm3 each time, and the amount of thiosulphate will be fixed at 15 cm3. During the heating stage of the experiment, a blue flame will be used throughout. Also the same Bunsen burner and gas tap will be used to maintain continuity. All of these precautions will make my final results more reliable and keep anomalies at a minimum so thus make the entire investigation more successful. Prediction I predict that as the temperature is increased the rate of reaction will increase. I also predict that as the concentration of the sodium thiosulphate increases the rate of reaction will increase. This means that both graphs drawn up in my analysis will have positive correlation, and will probably be curved as the increase in rate of reaction will not be exactly the same as the concentrationtemperature is increased. This can be justified by relating to the collision theory. When the temperature is increased the particles will have more energy and thus move faster. Therefore they will collide more often and with more energy. Particles with more energy are more likely to overcome the activation energy barrier to reaction and thus react successfully. If solutions of reacting particles are made more concentrated there are more particles per unit volume. Collisions between reacting particles are therefore more likely to occur. All this can be understood better with full understanding of t he collision theory itself: For a reaction to occur particles have to collide with each other. Only a small percent 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. The size of this activation energy is different for different reactions. If the frequency of collisions is increased the rate of reaction will increase. However the percent of successful collisions remains the same. An increase in the frequency of collisions can be achieved by increasing the concentration, pressure, or surface area. Concentration If the concentration of a solution is increased there are more reactant particles per unit volume. This increases the probability of reactant particles colliding with each other. Pressure If the pressure is increased the particles in the gas are pushed closer. This increases the concentration and thus the rate of reaction. Surface Area If a solid is powdered then there is a greater surface area available for a reaction, compared to the same mass of unpowdered solid. Only particles on the surface of the solid will be able to undergo collisions with the particles in a solution or gas. The particles in a gas undergo random collisions in which energy is transferred between the colliding particles. As a result there will be particles with differing energies. Maxwell-Boltzmann energy distribution curves show the distribution of the energies of the particles in a gas. The main points to note about the curves are: 1. There are no particles with zero energy. 2. The curve does not touch the x-axis at the higher end, because there will always be some particles with very high energies. 3. The area under the curve is equal to the total number of particles in the system. 4. The peak of the curve indicates the most probable energy. The activation energy for a given reaction can be marked on the distribution curve. Only particles with energy equal or greater than the activation energy can react when a collision occurs. Although Maxwell-Boltzmann distribution curves are for the particles in a gas, the same distributions can be used for the particles in a liquid or solid. Effects of a temperature change The graph below shows Maxwell-Boltzmann distribution graphs for a fixed mass of gas at two temperatures T1 and T2, where T2 is roughly 10?C higher than T1. The total area under the curve remains the same, since there is no change in the number of particles present. A small increase in temperature causes significant changes to the distribution energies. At the higher temperature: 1. The peak is at a higher energy. 2. The peak is lower. 3. The peak is broader. 4. There is a large increase in the number of particles with higher energies. It is the final change that results increase in rate, even with a relatively small increase in temperature. A small increase in temperature greatly increases the number of particles with energy greater than the activation energy. The shaded areas on the energy distribution curves show this. Effect of a catalyst A catalyst works by providing an alternative reaction pathway that has lower activation energy. A catalyst does not alter the Maxwell-Boltzmann distribution. Because a catalyst provides a reaction route of lower activation energy, however, a greater proportion of particles will have energy greater than the activation energy. Analysis In this experiment I have found that as the temperature and concentration is increased the time taken for the reaction to take place decreases. This means the rate of reaction increasers as it takes less time for a reaction to take place, so more take place per second. In the temperature experiment the time taken for a reaction to take place decreased by roughly 10 to 15 seconds for every 10?C increase in temperature, with the one anomaly being the 30?C reading. There is also a trend in the increase in rate of reaction as the temperature increases. The difference is always more or less 0.02 s-1, with the same exception. Using the graphs, with lines of best fit, I can draw a conclusion from my experiment. Firstly I can see that with the time graphs (that plot temperature and concentration against time taken for the reaction to take place) the graphs have negative correlation in both cases, meaning that as the temperatureconcentration increased the time taken for the reaction to take place decreases. The time graph for the temperature experiment has a much steeper curve than the one for the concentration experiment, meaning that the decrease in time taken for the reaction was far more rapid. Naturally, the above means that the both the graphs plotting rate against temperature and concentration have positive correlation as the temperature and concentration are increased so does the rate of reaction. This is because when the temperature is increased the particles will have more energy and thus move faster. Therefore they will collide more often and with more energy. Particles with more energy are more likely to overcome the activation energy barrier to reaction and thus react successfully, and when solutions of reacting particles are made more concentrated there are more particles per unit volume. Collisions between reacting particles are therefore more likely to occur. The graph for concentration shows that when the concentrations were relatively low (10, 15, 20 g/dm3), the increase of rate x1000 was also fairly small (increasing from 4.47 to 6.71 to 9.47). There was then a gradual increase in the difference, and between 30 and 35 g/dm3 the rate more than doubled from 17.90 to 37.56s-1. This shows that there are far more collisions at a concentration of 35 g/dm3 than at 30 g/dm3. The graph plotting time against the rate of reaction x1000 shows that the difference of rate between increasing temperatures (excluding the anomaly of 30?C) was pretty much regular, increasing in steps of 6-10 (9.17 to 15.37 to 24.28 to 31.67). However, once again there is a giant gap in the last temperature increase at 60?C the RoR x1000 is 31.67 s-1, and at 70?C it is 57.03 s-1. For this to fully make sense it is necessary to recap the collision theory briefly: For a reaction to occur particles have to collide with each other. Only a small percent 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. The size of this activation energy is different for different reactions. If the  frequency of collisions is increased the rate of reaction will increase. However the percent of successful collisions remains the same. An increase in the frequency of collisions can be achieved by increasing the concentration, pressure, or surface area.

Stalin: In the Wrong? :: essays research papers

Stalin, by many people today, would be considered a horrible man who had caused much harm to the world. This, of course, is in modern terms. History has a way of reshaping the ‘morality’ of events over a period of time. Take, for example, the Crusades. The majority of Europeans at the time vastly agreed with their purpose. Now, however, they are seen as a religious leader’s abuse of power and an unfortunate loss of life. Will the same reversal occur with the view of Stalin? After all, he did completely reshape a backwards society. Since we cannot conceivable travel into the future, Stalin will be assessed from acclaimed people of the past. These people will have no prejudice towards Stalin in their ideals because they will not have known of Stalin nor the Soviet Union. However, their overall opinions will not fluctuate based on Stalin and thus Stalin will be judged. Stalin will be evaluated by the following three distinguished historical intellectuals: Plato, Mac hiavelli and Sir James G. Frazer.   Ã‚  Ã‚  Ã‚  Ã‚  The first person we shall introduce to judge Stalin is the Athenian philosopher Plato. Plato, in his dialogue in the First Book of The Laws, suggests a very simple, yet effective, test for selecting and educating men who can be trusted as statesmen. This test, which later became known as the wine test, was supportive of Plato’s views. It was not simply enough to be a wise ex-soldier, as many people believe Plato choose them to be the most qualified. In the dialogue, Plato states that drunkenness loosens a man’s tongue, which gives the presents public an idea what he is really like. By this simple test, Plato would readily support Stalin. Stalin was well-known to drink everyone else â€Å"under the table†. In fact, Stalin imbibed much more than his fellow British counterpart, Sir Winston Churchill, and his successor, Khrushchev. Stalin, being a Georgian, took great pride in his raising on a diet of mutton and wine, and as he grew, found wine no t potent enough, preferring to consume vodka. Wine, he said, was merely ‘juice’. Stalin, when he drank, rarely fluctuated from what he said when he was sober, proving to be a very consistent man. However, the people that he had at his little get-togethers were not, and often he used the information obtained here to ‘purge’ later victims.   Ã‚  Ã‚  Ã‚  Ã‚  Plato saw the wine test not as a means for him or others to get drunk, but instead loosen the tongue.

Benefits of being Multilingual Essay

In today’s society, being one step ahead can account for a lot. In the modern day world, people of all cultures are constantly intercepting in one way or another, whether it be at work, in stores, or in their own neighborhoods. How could you live so close to someone and not being able to communicate with them? It’s nearly impossible. This reason, exactly, especially considering America’s diversity, is why being multilingual is pushed and praised so heavily across the world. Many of today’s youth look at being multilingual as a ‘scary’ thing, but why? It is scary because we fear the unknown. It is a problem that, multi-linguists is not common in urban American because the youth is ignorant to all its benefits. According to research done by ATLA, depending on your language background, you can become fluent in another language in as little as three months, or it may take you years. Every person is different, and the time it takes to learn a new language is based upon how much time you can devote to studying, your natural ability to learn languages, and your ultimate goal in learning the language. It is important to learn the language of others because of emigration. It is common to live just next door to someone not of your same decent or someone with the same culture background as yours. Being that this is so, you must know how to speak with them, if not just for courteous purposes. As well as if you work with someone, you might be placed in situations that would require you to partner up with someone of a different native tongue than yours, and if you cannot successfully converse then you will not perform so well, which could ultimately result in problems on your job. Also, when in school, you may be faced with a certain subject that catches your interest but the content may be published in a foreign language. Knowing another language could grant you access to materials you may have never had the opportunity to learn from. For more secretive people, if you make friends with someone who speaks another language as yourself, then you could hold a private conversation in a room full of people, and just because they aren’t fluent and you are, it would be like having your own private, or secret language. Aspects of money come to play as well when discussing benefits of multi-linguistics. If you can speak more than one language, especially one not common to your local area, then you are more at an advantage to someone who is only unilingual. Jobs are more likely to hire you over someone who can only speak English because of the scarcity of multilingual laborers. The traveling thing will also come into play, everyone secretly dreams to travel the world one day and visit all the lands of the unknown, and if you could break the language barrier, then your travels would be, probably, safer, more enjoyable, and more of a learning experience. As you can see, there are more than an infinite amount of reasons why we should explore other languages from around the world, and not only the common ones, but those that are less popular. Though learning a second language is both time consuming and requires tons of dedication, the benefits that you can reap are more than a reward.

Battle of Anzio in World War II

The Battle of Anzio commenced on January 22, 1944 and concluded with the fall of Rome on June 5. Part of the Italian Theater of World War II (1939-1945), the campaign was the result of the Allies inability to penetrate the Gustav Line following their landings at Salerno. British Prime Minister Winston Churchill sought to restart the Allied advance and proposed landing troops behind the German positions. Approved despite some resistance, the landings moved forward in January 1944. In the resulting fighting, the Allied landing force was soon contained due to its insufficient size and cautious decisions made by its commander, Major General John P. Lucas. The next several weeks saw the Germans mount a series of attacks which threatened to overwhelm the beachhead. Holding out, the troops at Anzio were reinforced and later played a key role in the Allied breakout at Cassino and the capture of Rome. Invading Italy Following the Allied invasion of Italy in September 1943, American and British forces drove up the peninsula until being halted at the Gustav (Winter) Line in front of Cassino. Unable to penetrate Field Marshal Albert Kesselrings defenses, British General Harold Alexander, commander of Allied forces in Italy, began assessing his options. In an effort to break the stalemate, Churchill proposed Operation Shingle which called for landings behind the Gustav Line at Anzio (Map). While Alexander initially considered a large operation that would land five divisions near Anzio, this was abandoned due to a lack of troops and landing craft.  Lieutenant General Mark Clark, commanding the US Fifth Army, later suggested landing a reinforced division at Anzio with the goal of diverting German attention from Cassino and opening the way for a breakthrough on that front.   Allied Plan Initially ignored by US Chief of Staff General George Marshall, planning moved forward after Churchill appealed to President Franklin Roosevelt. The plan called for Clarks US Fifth Army to attack along the Gustav Line to draw enemy forces south while Lucas VI Corps landed at Anzio and drove northeast into the Alban Hills to threaten the German rear. It was thought that if the Germans responded to the landings it would sufficiently weaken the Gustav Line to permit a breakthrough. If they did not respond, the Shingle troops would be in place to directly threaten Rome.  The Allied leadership also felt that should the Germans be able to respond to both threats, it would pin down forces that otherwise could be employed elsewhere. Field Marshal Harold Alexander. Public Domain As preparations moved forward, Alexander desired Lucas to land and quickly begin offensive operations into the Alban Hills. Clarks final orders to Lucas did not reflect this urgency and gave him flexibility regarding the timing of the advance. This may have been caused by Clarks lack of faith in the plan which he believed required at least two corps or a full army. Lucas shared this uncertainty and believed that he was going ashore with insufficient forces. In the days before landings, Lucas compared the operation to the disastrous Gallipoli campaign of World War I which had also been devised by Churchill and expressed concern that he would be scapegoated if the campaign failed. Armies Commanders Allies General Harold AlexanderLieutenant General Mark ClarkMajor General John P. LucasMajor General Lucian Truscott36,000 men increasing to 150,000 men Germans Field Marshal Albert KesselringColonel General Eberhard von Mackensen20,000 men rising to 135,000 men Landing Despite the misgivings of the senior commanders, Operation Shingle moved forward on January 22, 1944, with Major General Ronald Penneys British 1st Infantry Division landing north of Anzio, Colonel William O. Darbys 6615th Ranger Force attacking the port, and Major General Lucian K. Truscotts US 3rd Infantry Division landing south of the town. Coming ashore, Allied forces initially met little resistance and began moving inland. By midnight, 36,000 men had landed and secured a beachhead 2-3 miles deep at a cost of 13 killed and 97 wounded. Rather than move quickly to strike at the German rear, Lucas began strengthening his perimeter despite offers from the Italian resistance to serve as guides. This inaction irritated Churchill and Alexander as it undercut the value of the operation. Facing a superior enemy force, Lucas caution was justified to a degree, however most agree that he should have attempted drive further inland. German Response Though surprised by the Allies actions, Kesselring had made contingency plans for landings at several locations.  When informed of the Allied landings, Kesselring took immediate action by dispatching recently-formed mobile reaction units to the area. Also, he received control of three additional divisions in Italy and three from elsewhere in Europe from OKW (German High Command). Though he initially did not believe the landings could be contained, Lucas inaction changed his mind and by January 24, he had 40,000 men in prepared defensive positions opposite the Allied lines. Battling for the Beachhead The next day, Colonel General Eberhard von Mackensen was given command of the German defenses. Across the lines, Lucas was reinforced by the US 45th Infantry Division and US 1st Armored Division. On January 30, he launched a two-prong attack with the British attacking up the Via Anziate towards Campoleone while the US 3rd Infantry Division and Rangers assaulted Cisterna. In the fighting that resulted, the attack on Cisterna was repulsed, with the Rangers taking heavy losses. The fighting saw two battalions of the elite troops effectively destroyed. Elsewhere, the British gained ground up the Via Anziate but failed to take the town. As a result, an exposed salient was created in the lines. This bulge would soon become the target of repeated German assaults (Map). A Command Change By early February Mackensens force totaled over 100,000 men facing Lucas 76,400. On February 3, the Germans attacked the Allied lines with a focus on the Via Anziate salient. In several days of heavy fighting, they succeeded in pushing the British back. By February 10, the salient had been lost and a planned counterattack the next day failed when the Germans were tipped off by a radio intercept. On February 16, the German assault was renewed and Allied forces on the Via Anziate front were pushed back to their prepared defenses at the Final Beachhead Line before the Germans were halted by VI Corps reserves. The last gasps of the German offensive were blocked on February 20. Frustrated with Lucas performance, Clark replaced him with Truscott on February 22. General Sir Harold Alexander with Major General Lucian K. Truscott Jr. in the Anzio beachhead, Italy, 4 March 1944. Public Domain Under pressure from Berlin, Kesselring and Mackensen ordered another attack on February 29. Striking near Cisterna, this effort was repulsed by the Allies with around 2,500 German casualties. With the situation at a stalemate, Truscott and Mackensen suspended offensive operations until spring. During this time, Kesselring constructed the Caesar C defensive line between the beachhead and Rome. Working with Alexander and Clark, Truscott helped plan Operation Diadem which called for a massive offensive in May. As part of this, he was instructed to devise two plans. New Plans The first, Operation Buffalo, called for an attack to cut Route 6 at Valmontone to aid in trapping the German Tenth Army, while the other, Operation Turtle, was for an advance through Campoleone and Albano towards Rome. While Alexander selected Buffalo, Clark was adamant that US forces be the first to enter Rome and lobbied for Turtle. Though Alexander insisted on severing Route 6, he told Clark that Rome was an option if Buffalo ran into trouble. As a result, Clark instructed Truscott to be ready to execute both operations. Breaking Out The offensive moved forward on May 23 with Allied troops hitting the Gustav Line and beachhead defenses. While the British pinned Mackensens men at Via Anziate, American forces finally took Cisterna on May 25. By the end of the day, US forces were three miles from Valmontone with Buffalo proceeding according to plan and Truscott anticipating severing Route 6 the next day. That evening, Truscott was stunned to receive orders from Clark calling for him to turn his attack ninety degrees towards Rome. While the attack towards Valmontone would continue, it would be much weakened. A Controversial Decision Clark did not inform Alexander of this change until the morning of May 26 at which point the orders could not be reversed. Exploiting the slowed American attack, Kesselring moved parts of four divisions into the Velletri Gap to stall the advance. Holding Route 6 open until May 30, they allowed seven divisions from the Tenth Army to escape north. Forced to reorient his forces, Truscott was not able to attack towards Rome until May 29. Encountering the Caesar C Line, VI Corps, now aided by II Corps, was able to exploit a gap in the German defenses. By June 2, the German line collapsed and Kesselring was ordered to retreat north of Rome. American forces led by Clark entered the city three days later (Map). Aftermath The fighting during the Anzio campaign saw Allied forces sustain around 7,000 killed and 36,000 wounded/missing. German losses were around 5,000 killed, 30,500 wounded/missing, and 4,500 captured. Though the campaign ultimately proved successful, Operation Shingle has been criticized for being poorly planned and executed. While Lucas should have been more aggressive, his force was too small to achieve the objectives it was assigned. Also, Clarks change of plan during Operation Diadem allowed large parts of the German Tenth Army to escape, allowing it to continue fighting through the rest of the year. Though criticized, Churchill relentlessly defended the Anzio operation claiming that though it failed to achieve its tactical goals, it succeeded in holding German forces in Italy and preventing their redeployment to Northwest Europe on the eve of the Normandy invasion.