The kinetic theory Essay Example for Free

The kinetic theory Essay In this investigation, I will be studying the factors that affect the rate of reaction. In this case, the reaction between hydrochloric acid and sodium thiosulphate. Na2S2O3 (aq)+ 2HCl(aq) 2NaCl(aq)+S(s)+SO2(g) When hydrochloric acid is added to sodium thiosulphate, the chemicals react giving solid sulphur as one of the products. This is a precipitation reaction. By watching the speed at which the sulphur has formed, we can find out the rate of reaction. A cross can be marked on a piece of paper, and a flask of sodium thiosulphate can be placed on top. By adding hydrochloric acid to the sodium thiosulphate, we can time how long it takes for the view of the cross to become obscured by the sulphur. We can then find out the rate of the reaction. What is Rate? Chemical reactions can be seen everywhere, whether an explosion, which is extremely fast, to something very slow, like the rusting of a metal. It is not enough just to know whether something is fast or slow however. Rate is a measure of the change that happens in a single unit of time. For example, if a car travels 40 km in half an hour, it is travelling at 80 km/h. For a chemical reaction to take place, some bonds in the reactants must be broken. The colliding particles must have enough energy to break these bonds. This minimum amount of energy is called the activation energy. Only the very fastest moving particles have enough energy to break bonds. In gases, liquids and in solution, the particles move at a range of speeds. Some are moving very slowly and others are moving very fast. To react, particles must collide with enough energy and in the correct orientation for bonds to be broken. If there is not enough kinetic energy, the particles barely touch, and the reaction does not happen. If the kinetic energy of the particles is just right, they hit each other and form new bonds. For a reaction to take place, the alignment of the molecules must also be correct. If two or more molecules collide, but are not orientated correctly, a reaction cannot take place. Variables Concentration of Thio If the concentration of thio is increased, the rate of reaction is also increased. This is because in dilute acid, there are not many acid particles. This means there is a more remote chance of an acid particle, hitting a sodium thiosulphate particle. In a more concentrated acid, there are more acid particles. There is now more chance of an acid particle colliding with a sodium thiosulphate particle, and so more chance of a collision. I have chosen this variable to use, as it will be possible to get a wide range of results with relative ease. I also feel that there will be a significant enough range of values in the results to make an effective graph. I could change this variable by adding water to the sodium thiosulphate to make it less concentrated. I will need to keep the volume constant throughout the experiment, so I could, for example use 40 cm3 of sodium thiosulphate and 10 cm3 of water, and then 30/20 etc. Temperature At low temperatures, particles of reacting substances do not have much energy. However, when the substances are heated, the particles take in energy. This causes them to move faster and collide more often. The collisions have more energy; so more collisions are successful. Therefore, the rate of reaction increases. This is called the kinetic theory. A reaction goes approximately twice as fast when the temperature is increased by 10 degrees. This is why it is important to keep this variable constant . To do this; I will need to do the experiment on the same day if possible. This ensures that the differences in room temperature, however small, do not affect the rate of reaction. Surface Area In a reaction containing a solid, its surface area has a large effect on the rate of reaction. If the surface area of the solid is small, the acid particles can only collide with the atoms in the outer layer of the solid. But if the solid has a large surface area, much more of the atoms are exposed, so there is a greater chance of one of these atoms colliding with an acid particle, and increasing the rate of reaction. However, in my experiment, I will not be using any solids, so this variable will not affect my experiment. Use of a Catalyst A catalyst is a substance that changes the rate of a chemical reaction but remains chemically unchanged itself. It does this by lowering the activation energy; this is the amount of energy needed in order to achieve a successful collision.

Descartes Third Meditation :: essays research papers

Meditation III   Ã‚  Ã‚  Ã‚  Ã‚  In Descartes Third Meditation, he establishes arguments to prove the existence of God. Descartes believes in â€Å"Cogito Ergo Sum† this means I think therefore I am. The â€Å"I† in this sentence means the soul. Descartes believes the existence of the mind is better known than the existence of the body. If my soul thinks then I exist. The Cogito proves the existence of self or the mind; this is not the same for the theory of God. Descartes has two arguments in the Third meditation. The arguments are the cause of his idea of God and the cause of his existence now. In the third meditation Descartes uses his existence as an example to find out whether God exist. Descartes explanation is whatever he perceived clear and distinct is true. The idea of the existence of God could have been caused by something out side of himself. Something had to put the idea of God in his mind for him to think about the existence of God. Descartes says, â€Å"I must examine whether there is a God, and, if there is, whether he can be a deceiver. Descartes has to prove that God exists and that he is no deceiver. Descartes then explains that the idea of God is the idea of a perfect or Supreme Being. A perfect being could have set this idea in our minds. He discovers that a perfect thing exists and that perfect being is defined as God. Descartes says, â€Å"All these attributes are such that, the more carefully I concentrate on them, the less possible it seems that they could have originated from me alone. So from what has been said it must be concluded that God necessarily exists.† Descartes also reveals that God is not a deceiver. Descartes knows that a perfect being has no faults. Deception depends on some defect or fault. Therefore, if a perfect being has no faults then that perfect being can not be a deceiver.

Fan, Ying : Branding the Nation: What Is Being Branded?

Fan, Ying : Branding the nation: What is being branded? Journal of Vacation Marketing Volume 12 Number 1. 2005 p. 4-13 Abstract: The paper by Fan explains what nation branding is. So first the difference between Nation branding and Nation brand is explained. Every Nation has a certain image with or without Nation branding. It examines the concept of nation branding, focusing especially on the question of what is being branded. The paper tries to explain what nation branding is and tries to explain the differences between on the one hand nation branding and product branding and on the other hand nation branding and product- country image. Furthermore it discusses paradoxical issues of nation branding and tries to give a broader context in which nation branding can be applied. But to find out how nation branding could help economic development in a country , more research is needed. It is hard to say how important the role of nation branding really is. Key Words: ation branding, country branding, country-of-origin effect, product- country image, place marketing The author: The paper is written by Ying Fan a senior lecturer at Brunel Business School, Brunel University in London. Dr Fan has held faculty positions at the universities of Lincoln, Hertfordshire and Durham. His research interests surround branding and marketing communications, and cross-cultural management issues. Topic: Branding the nation: What is being branded? The major topic of the paper is what nation branding is and what the purpose of nation branding is. Research question : What is being branded? Is a nation brand a separate entity, or an element in the product brand? What is the direction of the correlation between countries that have produced strong brands and those that are strong brands themselves ? Method : The research method is a literary analysis Material and Structure of the paper: On the first page of his paper contact informations, informations on the author including a photo of Fan are given. An Abstract sums up the Keywords and gives an overview over the article. All in all the paper of Fan is 9 pages long and is structured in the chapters: Introduction What is Nation Branding? What is being branded? Nation branding and product branding Nation brand image and product-country image Paradoxes The broader context For a further understanding Fan gives 3 Tables: Terms used in the literature ; Examples of nation branding where he gives 5 examples and explains what is being branded and a table on Comparison between nation branding and product branding . In his paper Fan makes indirect citations which are listed in the references. Here the references are ordered by appearance in the text not alphabetically. The paper is easy to read and understand, it gives a good overview of the topic nation branding. The structure is easy to follow. The paper is anonymously refereed. Finding of the article : The author points out that there is no single definition on nation branding but gives a working definition for the paper: ‘Nation branding concerns applying branding and marketing communications techniques to promote a nation’s image. Nation branding can be used in different ways: using the nation’s image to promote sales and exports ; place branding which is part of tourism marketing ; political marketing for example the expression â€Å"axis of evil†; Nation branding in it's true sense like Cool Britannia. The author points out that a nation is not a product in the conventional sense . The Nation itself can hardly be changed, the benefits are purely emotional, the Image is complicated and the ownership is unclear. A nation brand is not centered on any specific product, service or cause that can be promoted directly to the customer. But Nation branding concerns a countries whole image, covering political, economic, historical and cultural dimensions. A Nation has not one but multiple images. What image is retrieved depends on the audience , the context and the time. The author finds out that negative national image does not necessarily affect the purchase of products made by that country, by giving the example of Japan and China. The author tries to find out the direction of the correlation between countries that have produced strong brands and those that are strong brands themselves . Nation branding must be distinctive and help the country to position itself against competitors . A difficulty is that an international audience have a different degree of knowledge of a nation and each country has different cultural values, thus decodes the message differently. Nation branding often try to communicate a single image or message to different audiences in different countries . This renders for the author the message meaningless, but to try to be all things to all people will in the opinion of the author inevitably fail . What is the message a nation wants to send, give up a old but unique image in favor of the new image. This can fail like for example â€Å"Cool Britannia† did. Another difficulty in nation branding is that a national identity is very difficult to define. Furthermore in nation branding, an understanding of the customers’ existing perception of the nation is very important. A certain image is made over time. Another important aspect of nation branding is the internal audience. The author points out that Nation branding is just one part of a marketing strategy which is part of the business strategy and that often nation branding is overestimated even if it is a powerful tool. It is for example not sufficient for the country to promote its image enthusiastically to other nations if the economic basis for the nation brand is not there or the political situation is unstable. The image problem of a region or nation most often results from political and socio-economic troubles which must be solved, nation branding will not solve a country’s problems but only serves as the final touch .

Triassic-Jurassic Mass Extinction

Over the entire 4.6 billion year history of the Earth, there have been five major mass extinction events. These catastrophic events completely wiped out large percentages of all of the life around at the time of the mass extinction event. These mass extinction events shaped how the living things that did survive evolve and new species appear. Some scientists also believe we are currently in the middle of the sixth mass extinction event that could last for a million years or more. The Fourth Major Extinction The fourth major mass extinction event happened around 200 million years ago at the end of the Triassic Period of the Mesozoic Era to usher in the Jurassic Period. This mass extinction event was actually a combination of smaller mass extinction periods that happened over the final 18 million years or so of the Triassic Period. Over the course of this extinction event, it is estimated more than half of the known living species at the time completely died out. This allowed dinosaurs to thrive and take over some of the niches left open due to the extinction of species that had previously held those types of roles in the ecosystem. What Ended the Triassic Period? There are several different hypotheses on what caused this particular mass extinction at the end of the Triassic Period. Since the third major mass extinction actually is thought to have occurred in several small waves of extinctions, it is entirely possible that all of these hypotheses, along with others that may not be as popular or thought of as of yet, could have caused the overall mass extinction event. There is evidence for all of the causes proposed. Volcanic Activity:Â  One possible explanation for this catastrophic mass extinction event is unusually high levels of volcanic activity. It is known that large numbers of flood basalts around the Central America region occurred around the time of the Triassic-Jurassic mass extinction event. These enormous volcano eruptions are thought to have expelled huge amounts of greenhouse gases like sulfur dioxide or carbon dioxide that would quickly and devastatingly increase the global climate. Other scientists believe it would have aerosols expelled from these volcanic eruptions that would actually do the opposite of the greenhouse gases and end up cooling the climate significantly. Climate Change:Â  Other scientists believe it was more of a gradual climate change issue that spanned the majority of the 18 million year time span attributed to the end of the Triassic mass extinction. This would have led to changing sea levels and even possibly a change in the acidity within the oceans that would have affected species living there. Meteor Impact: A less likely cause of the Triassic-Jurassic mass extinction event may be attributed to asteroid or meteor impact, much like what is thought to have caused the Cretaceous-Tertiary mass extinction (also known as the K-T Mass Extinction) when the dinosaurs all went extinct. However, this is not a very likely reason for the third mass extinction event because there has been no crater found that would indicate it could create devastation of this magnitude. There was a meteor strike that dates to about this time period, but it was rather small and is not thought to have been able to cause a mass extinction event that is thought to have wiped out more than half of all living species on both land and in the oceans. However, the asteroid impact may have very well caused a local mass extinction that is now attributed to the overall major mass extinction that ended the Triassic Period and ushered in the beginning of the Jurassic Period.