We are ready to represent the best custom paper writing assistance that can cope with any task like Thermonuclear physics even at the eleventh hour. The matter is that we posses the greatest base of expert writers. Our staff of freelance writers includes approximately 300 experienced writers are at your disposal all year round. They are striving to provide the best ever services to the most desperate students that have already lost the hope for academic success. We offer the range of the most widely required, however, not recommended for college use papers. It is advisable to use our examples like Thermonuclear physics in learning at public-education level. Get prepared and be smart with our best essay samples cheap and fast! Get in touch and we will write excellent custom coursework or essay especially for you.
The physics of high-temperature, multi-keV, collisionless plasmas, usually immersed in a magnetic field of complex geometry, is dominated by the behavior of unique many-body systems in which collective phenomena dominate over rare two-body collisions. These plasmas are usually far from the thermodynamic equilibrium, due to sources of mode-excitation energy that owe their existence to factors including electrodynamic forces with spatial inhomogeneties (this is the case in magnetic or inertial confinement systems with gradients of density, temperature, magnetic field, etc.); the presence of high-energy subgroups of particles (or beams); and large-amplitude electromagnetic waves that propagate in the plasma and transfer their energy, inducing strong nonlinear interactions among background collective modes and charged particles.
At MIT, pioneering investigations on the physical properties of high temperature plasmas at very high densities have been carried out for more than two decades by the Alcator experimental program. Alcator is an acronym for the Latin phrase Alto Campo Torus, meaning high field torus. The Alcator A and C tokamaks in the 170s and 180s operated at very high magnetic fields (up to 1 Tesla) and ultra high densities (ne = x 1015cm), and surpassed the minimum required value of the plasma density times every confinement time for fusion breakeven (although at lower temperatures then necessary for true breakeven conditions). At lower densities, significant toroidal plasma currents were generated efficiently by high-power traveling electromagnetic waves with frequencies in the GHz range.
The Alcator confinement and the current drive experiments both received the Excellence in Plasma Physics Research Award of the American Physical Society. Following these successes, the Plasma Science and Fusion Center proceeded to build a new, state-of-the-art high magnetic field experiment, Alcator C-Mod, which has an advanced magnetic divertor and allows for optimal shaping of the plasma cross-section. PSFC scientists have achieved truly exciting results by being able to heat high density plasmas in C-Mod to 6 keV temperature by injecting multi-MW radio frequency power at the ion cyclotron frequency (80 MHz). The ultimate goal of these experiments is to find a path to achieve thermonuclear ignition in laboratory experiments. Thus, a considerable effort is being devoted to the Ignitor project, first proposed and studied at MIT; this program has begun the construction of prototype components in Italy for the first machine capable of achieving fusion burn conditions.
We should also mention here the MIT experimental program in Inertial Fusion. Researchers and graduate students carry out experiments off-site at the Nova laser facility at the Lawrence Livermore National Laboratory, as well as at the OMEGA facility at the University of Rochester. Their objective is to understand the physics of pellet implosion and fusion products during intense laser irradiation of targets.
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Monday, June 18, 2012
Skill acquisition
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At the age of 14, I was preparing for the National Table Tennis Championships in England. A working class background meant that finances and equipment for training were scarce. I did not have a table tennis table in the house or the funds to hire a table at the local hall. There was a weekly club practice session on a Sunday night. This was my only opportunity for physical practice. My father, a sports teacher of 0 years suggested that I buy a book and video on stroke play and table tennis in general. The research article I have found highlights some of the benefits of mental practice both in conjunction with or in the absence of physical training.
As my physical training could only by performed on a weekly basis, I needed to make the most of the short time I had. I set up a programme by which I would spend at least one hour per day with my bat in hand and mentally engaging the games I would face in the tournament. I went through the many options within the ,5 & 7 ball attack and the possible returns from these combinations; the returns from each different type of serve; which serve would produce the best options for a winning shot; how to speed up the game; how to slow down the game; how I could beat my opponent before I had played a shot. The book I purchased had a flick book section at the edge of each page. As you read through each section, there was a 150 flick, flick book sequence of the shot/serve/return depending on the section. Going through the shots in the flick book and then visualising myself in the picture allowed me to practice the shots without being at the table or having an opponent.
As my ‘coach’ was not able to be with me during this practise time, I had to be very strict with myself. I had the desire to compete to the best of my abilities at the Nationals and the only way that I saw I could achieve this, with my limited resources, was to be very meticulous in my mental training. I was prepared for anything that might arise at the Nationals. The research article shows that “Mental practice is effective”. As my mental practice was complimenting my weekly physical practice I was receiving the optimum benefits. As I had been playing table tennis for a year by this stage, I felt I was beyond the novice stage. The research shows that the fact that I had reached a minimum standard of proficiency, I was able to gain greater benefits from this mental practice. The fact that I was able to actually see myself in the flick book images was a huge advantage to me. The research shows that by using internal perspective, I was able to gain greater benefits from my time. The time spent rehearsing mentally not only helped me to develop my motor skill acquisition and decision making but the research shows that this practice also helped to reduce my pre-competition anxiety. Looking back I would agree that I had very little anxiety when it came to the competitions. I truly believe that this was due to my mental practice.
Although I had dedicated significantly less time to physical practice in comparison to my opponents, I feel that my time spent during these practices was more productive as I had greater time on task due to my mental practice. The Nationals went well that year, I received a letter in the mail two days later requesting my presence on a National training camp for an under 16 International game with the Home Nations of Scotland, Wales and Ireland and a match with Yugoslavia at the end of the year. .
I believe that this training technique emphasises the adage that ‘knowledge is power‘. I went into the table tennis Nationals with every possible combination of possibilities that may arise. Some of these did arise and I was able to overcome them to win the tournament. By transferring this technique into my other sports I feel that I have been able to achieve success at a greater level than my competitors. As long as my mental training is complimenting my physical training I will continue to use it.
Reference
Romero. K, Silvestri. L. 10. Cognitive Motor Learning. Journal of Instructional Psychology; Dec0, Vol. 17 Issue 4, p18-.
Mind that the sample papers like Skill acquisition presented are to be used for review only. In order to warn you and eliminate any plagiarism writing intentions, it is highly recommended not to use the essays in class. In cases you experience difficulties with essay writing in class and for in class use, order original papers with our expert writers. Cheap custom papers can be written from scratch for each customer that entrusts his or her academic success to our writing team. Order your unique assignment from the best custom writing services cheap and fast!
At the age of 14, I was preparing for the National Table Tennis Championships in England. A working class background meant that finances and equipment for training were scarce. I did not have a table tennis table in the house or the funds to hire a table at the local hall. There was a weekly club practice session on a Sunday night. This was my only opportunity for physical practice. My father, a sports teacher of 0 years suggested that I buy a book and video on stroke play and table tennis in general. The research article I have found highlights some of the benefits of mental practice both in conjunction with or in the absence of physical training.
As my physical training could only by performed on a weekly basis, I needed to make the most of the short time I had. I set up a programme by which I would spend at least one hour per day with my bat in hand and mentally engaging the games I would face in the tournament. I went through the many options within the ,5 & 7 ball attack and the possible returns from these combinations; the returns from each different type of serve; which serve would produce the best options for a winning shot; how to speed up the game; how to slow down the game; how I could beat my opponent before I had played a shot. The book I purchased had a flick book section at the edge of each page. As you read through each section, there was a 150 flick, flick book sequence of the shot/serve/return depending on the section. Going through the shots in the flick book and then visualising myself in the picture allowed me to practice the shots without being at the table or having an opponent.
As my ‘coach’ was not able to be with me during this practise time, I had to be very strict with myself. I had the desire to compete to the best of my abilities at the Nationals and the only way that I saw I could achieve this, with my limited resources, was to be very meticulous in my mental training. I was prepared for anything that might arise at the Nationals. The research article shows that “Mental practice is effective”. As my mental practice was complimenting my weekly physical practice I was receiving the optimum benefits. As I had been playing table tennis for a year by this stage, I felt I was beyond the novice stage. The research shows that the fact that I had reached a minimum standard of proficiency, I was able to gain greater benefits from this mental practice. The fact that I was able to actually see myself in the flick book images was a huge advantage to me. The research shows that by using internal perspective, I was able to gain greater benefits from my time. The time spent rehearsing mentally not only helped me to develop my motor skill acquisition and decision making but the research shows that this practice also helped to reduce my pre-competition anxiety. Looking back I would agree that I had very little anxiety when it came to the competitions. I truly believe that this was due to my mental practice.
Although I had dedicated significantly less time to physical practice in comparison to my opponents, I feel that my time spent during these practices was more productive as I had greater time on task due to my mental practice. The Nationals went well that year, I received a letter in the mail two days later requesting my presence on a National training camp for an under 16 International game with the Home Nations of Scotland, Wales and Ireland and a match with Yugoslavia at the end of the year. .
I believe that this training technique emphasises the adage that ‘knowledge is power‘. I went into the table tennis Nationals with every possible combination of possibilities that may arise. Some of these did arise and I was able to overcome them to win the tournament. By transferring this technique into my other sports I feel that I have been able to achieve success at a greater level than my competitors. As long as my mental training is complimenting my physical training I will continue to use it.
Reference
Romero. K, Silvestri. L. 10. Cognitive Motor Learning. Journal of Instructional Psychology; Dec0, Vol. 17 Issue 4, p18-.
Mind that the sample papers like Skill acquisition presented are to be used for review only. In order to warn you and eliminate any plagiarism writing intentions, it is highly recommended not to use the essays in class. In cases you experience difficulties with essay writing in class and for in class use, order original papers with our expert writers. Cheap custom papers can be written from scratch for each customer that entrusts his or her academic success to our writing team. Order your unique assignment from the best custom writing services cheap and fast!
Tuesday, June 5, 2012
The Brown Pelican
We are ready to represent the best custom paper writing assistance that can cope with any task like The Brown Pelican even at the eleventh hour. The matter is that we posses the greatest base of expert writers. Our staff of freelance writers includes approximately 300 experienced writers are at your disposal all year round. They are striving to provide the best ever services to the most desperate students that have already lost the hope for academic success. We offer the range of the most widely required, however, not recommended for college use papers. It is advisable to use our examples like The Brown Pelican in learning at public-education level. Get prepared and be smart with our best essay samples cheap and fast! Get in touch and we will write excellent custom coursework or essay especially for you.
The chemical DDT almost caused the demise of the brown pelican (Pelecanus occidentalis) in the 160s. Pelicans exposed to DDT laid eggs with thin or non-existent shells. Since DDT was banned in 17, brown pelicans have made a remarkable recovery.
Increased efforts for seabird restoration, research, and monitoring are clearly needed in Californias four national marine sanctuaries, Gulf of the Farallones, Cordell Bank, Monterey Bay, and Channel Islands. Over the past 00 years, seabird populations in California have been negatively impacted by a multitude of anthropogenic threats, especially oil pollution, gill net fishing, contaminants, disturbance at breeding colonies, loss of nesting habitats, and depredation. Populations of several resident seabird species have declined and/or experienced poor reproduction. These include ashy storm-petrel, brown pelican, common murre, marbled and Xantuss murrelets, and least tern. Even with substantial efforts over the past few decades by federal and state agencies to protect seabirds, many populations and breeding colonies have not recovered to historic sizes or distributions, apparently due to a significant extent to massive past impacts and continuing anthropogenic impacts from several sources. Oil pollution, in particular, will occur into the foreseeable future given extensive oil tanker traffic into Los Angeles, San Francisco, and other ports; continued offshore oil production in Southern California; and chronic, illegal discharges by the shipping industry. Restoration projects are needed to reduce the impacts of certain anthropogenic sources on seabird populations. In conjunction with other management actions, restoration projects should allow many seabird populations to better sustain future injuries and to recover over time.
The National Marine Sanctuary Program has become a major partner with the California Department of Fish and Game, U.S. Fish and Wildlife Service, and the National Park Service to develop and implement large-scale restoration projects for seabirds in California, using funds from oil spill settlements. The first major seabird restoration project was initiated in 15 and aims to re-establish a former breeding colony of common murres at Devils Slide Rock south of San Francisco. About halfway through its 10-year planned duration, this project has had considerable success towards reaching this aim, with about 75 breeding pairs of common murres in 1. A second project, initiated in 18, involves public acquisition of residual old-growth forest in the Gazos Creek watershed.
Common murres (Uria aalge) nest in the densest colonies of all seabirds. Females lay one egg per season, holding the large pointed egg between their legs. Egg losses are high because of predation and disturbance by eagles and gulls.
The acquired land is used as nesting habitat by threatened marbled murrelets. By effectively managing this property, potential loss of nesting habitat through logging has been prevented, and reduced forest fragmentation and reduced disturbance should lead to reduced nest depredation and increased breeding success in this and neighboring areas. These two projects have helped to restore seabirds in the Gulf of the Farallones, Cordell Bank, and northern Monterey Bay national marine sanctuaries, using funds from the Apex Houston oil spill settlement.
Mind that the sample papers like The Brown Pelican presented are to be used for review only. In order to warn you and eliminate any plagiarism writing intentions, it is highly recommended not to use the essays in class. In cases you experience difficulties with essay writing in class and for in class use, order original papers with our expert writers. Cheap custom papers can be written from scratch for each customer that entrusts his or her academic success to our writing team. Order your unique assignment from the best custom writing services cheap and fast!
The chemical DDT almost caused the demise of the brown pelican (Pelecanus occidentalis) in the 160s. Pelicans exposed to DDT laid eggs with thin or non-existent shells. Since DDT was banned in 17, brown pelicans have made a remarkable recovery.
Increased efforts for seabird restoration, research, and monitoring are clearly needed in Californias four national marine sanctuaries, Gulf of the Farallones, Cordell Bank, Monterey Bay, and Channel Islands. Over the past 00 years, seabird populations in California have been negatively impacted by a multitude of anthropogenic threats, especially oil pollution, gill net fishing, contaminants, disturbance at breeding colonies, loss of nesting habitats, and depredation. Populations of several resident seabird species have declined and/or experienced poor reproduction. These include ashy storm-petrel, brown pelican, common murre, marbled and Xantuss murrelets, and least tern. Even with substantial efforts over the past few decades by federal and state agencies to protect seabirds, many populations and breeding colonies have not recovered to historic sizes or distributions, apparently due to a significant extent to massive past impacts and continuing anthropogenic impacts from several sources. Oil pollution, in particular, will occur into the foreseeable future given extensive oil tanker traffic into Los Angeles, San Francisco, and other ports; continued offshore oil production in Southern California; and chronic, illegal discharges by the shipping industry. Restoration projects are needed to reduce the impacts of certain anthropogenic sources on seabird populations. In conjunction with other management actions, restoration projects should allow many seabird populations to better sustain future injuries and to recover over time.
The National Marine Sanctuary Program has become a major partner with the California Department of Fish and Game, U.S. Fish and Wildlife Service, and the National Park Service to develop and implement large-scale restoration projects for seabirds in California, using funds from oil spill settlements. The first major seabird restoration project was initiated in 15 and aims to re-establish a former breeding colony of common murres at Devils Slide Rock south of San Francisco. About halfway through its 10-year planned duration, this project has had considerable success towards reaching this aim, with about 75 breeding pairs of common murres in 1. A second project, initiated in 18, involves public acquisition of residual old-growth forest in the Gazos Creek watershed.
Common murres (Uria aalge) nest in the densest colonies of all seabirds. Females lay one egg per season, holding the large pointed egg between their legs. Egg losses are high because of predation and disturbance by eagles and gulls.
The acquired land is used as nesting habitat by threatened marbled murrelets. By effectively managing this property, potential loss of nesting habitat through logging has been prevented, and reduced forest fragmentation and reduced disturbance should lead to reduced nest depredation and increased breeding success in this and neighboring areas. These two projects have helped to restore seabirds in the Gulf of the Farallones, Cordell Bank, and northern Monterey Bay national marine sanctuaries, using funds from the Apex Houston oil spill settlement.
Mind that the sample papers like The Brown Pelican presented are to be used for review only. In order to warn you and eliminate any plagiarism writing intentions, it is highly recommended not to use the essays in class. In cases you experience difficulties with essay writing in class and for in class use, order original papers with our expert writers. Cheap custom papers can be written from scratch for each customer that entrusts his or her academic success to our writing team. Order your unique assignment from the best custom writing services cheap and fast!
Rates of reactions between HCL and magnesium ribbon
We are ready to represent the best custom paper writing assistance that can cope with any task like Rates of reactions between HCL and magnesium ribbon even at the eleventh hour. The matter is that we posses the greatest base of expert writers. Our staff of freelance writers includes approximately 300 experienced writers are at your disposal all year round. They are striving to provide the best ever services to the most desperate students that have already lost the hope for academic success. We offer the range of the most widely required, however, not recommended for college use papers. It is advisable to use our examples like Rates of reactions between HCL and magnesium ribbon in learning at public-education level. Get prepared and be smart with our best essay samples cheap and fast! Get in touch and we will write excellent custom coursework or essay especially for you.
Rates of reactions between HCL and magnesium ribbon
Aim
I plan to investigate the effect of concentration of acid, in the reaction between dilute hydrochloric acid and magnesium ribbon. The rate of a chemical reaction is a measure of how fast the reaction takes place. It is important to know that a rapid reaction is completed in a short period of time. Some reactions are very fast, for example; the formation of silver chloride precipitates when silver nitrate and hydrochloric acid solutions are mixed. In this investigation I will test different concentrations of acid reacting with magnesium.
/Plan
To investigate what effect concentration of sodium thiosulphate has on the rate of reaction. The volume of HCL needs to be kept at 10cm constantly each time. Start with 60cm of sodium thiosulphate. Last reaction will have only 10cm of sodium thiosulphate.
Reactions will be completed when the x disappears, for the timing to stop. Three reactions will be made for each test; this is done to gain the different averages.
Introduction
I will be conducting an experiment on the rate of reaction for my GCSE coursework. I will be doing this coursework for a period of two weeks. We will be reacting sodium thiosulphate with hydrochloric acid. I will be investigating the effects had on rate of reaction.
When sodium thiosulphate and hydrochloric are mixed, a yellow precept of sulphur is produced. The solution becomes increasingly difficult to see through as more and more sulphur is formed.
Prediction
My prediction is that as the concentration of the hydrochloric acid increases, the time taken for the magnesium to disappear decreases. I predict that when the concentration of the hydrochloric acid doubles, the rate of the reaction doubles.
Background Knowledge
Rate is a measure of how fast or slow something is. For example, Silver Chloride precipitating (this is a very fast reaction) and Concrete setting (it may take a couple of days for concrete to harden). Rate is a measure of the change that happens in a single unit of time. Any suitable unit of time can be used - a second, a minute, an hour and even a day.
To find the rate of reaction, you should measure The amount of reactant used up per unit of time or the amount of a product produced per unit of time.
We are going to do an experiment on the rate of reaction. We are using acid and magnesium strips to test the rate of reaction.
Rates of reaction can be varied by a number of factors
? The concentration of the acid in which the magnesium is placed,
? The temperature of the acid and
? The size of the surface area of the magnesium strip.
Why rate changes with concentration If the concentration of the acid is increased, the reaction goes faster.
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. In dilute acid, there are not so many acid particles. This means there is not much chance of an acid particle hitting a magnesium atom.
. Here the acid is more concentrated - there are more acid particles in it. There is now more chance of a successful collision occurring.
The more successful collisions there are the faster the reaction.
This idea also explains why the reaction between magnesium and hydrochloric acid slows down as time goes on
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. At the start, there are plenty of magnesium atoms and acid particles. But they get used up during successful collisions.
. After a time, there are fewer magnesium atoms, and the acid is less concentrated. So the reaction slows down.
Why rate changes with the 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 of them are successful. Therefore the rate of reaction increases.
Why rate increases with surface area The reaction between the magnesium and acid is much faster when the metal is powdered
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. Acid particles can collide only with magnesium atoms on the outside of the metal.
. When the metal is powdered, many more atoms are exposed. So there is a greater chance of successful collisions.
For my experiment my independent variable will be the concentration of the acid. I chose this as my independent variable as I feel this is the safest and easiest way to carry out the experiment. If I was to choose the temperature of the acid as my independent variable, and if I were to heat the acid too much it may boil and produce a corrosive gas, which would life threatening. It would be difficult to work out an accurate reading of the surface area if I was to choose the surface area as my independent variable.
Linking prediction to theory
Reaction rate and concentration.
The collision theory describes how the rate of reaction increases (the time taken for the magnesium ribbon to disappear when it is reacted with hydrochloric acid) when the concentration of HCL increases. As the reaction continues, the concentration of the reacting substances decreases and so does the rate of reaction. The reaction is speeded up if the number of collisions is increased. The higher the concentration of HCL you use, the less time it takes for the magnesium to disappear and so the rate reaction increases. If the activation energy is high only a small amount of particles will have enough energy to react so the reaction rate would be very small, however the activation energy is very low the number of particles with that amount of energy would be so high, so start, so the reaction rate would be higher.
Apparatus
Hydrochloric acid( mole)
Water(to dilute acid)
10ml testube
magnesium(cm long)
stop clock(sensitivity 1/10s)
beaker
In order to conduct any type of experiment, you need equipment. The equipment I used was a
Measuring Cylinder
Small measuring cylinder
Flask
beakers
Pad (marked with black cross) white cross
Timer
Method
To get the amount of magnesium and the amount of hydrochloric acid to use in the situation, we have to use an excess of acid so that all of the magnesium disappears.
An equation for the reaction
Magnesium + hydrochloric acid magnesium chloride + hydrogen
Mg(s) + HCL(aq)Mgcl(aq) + H(g)
1mole moles 1mole 1mole
So we can say that one mole of magnesium reacts with moles of hydrochloric acid. Throughout the experiment, we diluted the acid solution using water, as we did this the concentration of the acid decreased. Then 8ml of acid and ml of water solution on the magnesium, measured time taken for magnesium to disappear using stop clock. Then 7ml of acid and ml of acid, repeated as above. This way the rate of reaction(the time taken for the magnesium to disappear) was measured accurately for a fair test.
Results
The results for the time taken for magnesium to disappear when it is placed in different concentrations of acid are summarised below.
Analysis of results
From the results in the table and the graph we can see a steady increase in the rate of reaction as the concentration of the acid decreases. This complies with my prediction. The graph shows that there is an increase in the rate of reaction as the concentration increases because the graph has its largest gradient or it is steepest at this point. When the graph was made into 1/time the result should have been a straight line graph but it did not turn out this way even though concentration~1/time. This 1/time graph could be wrong because of inaccurate results so there seems to be no relationship between the concentration graph and the 1/time graph. We can see from the rate of reaction graph that when the concentration roughly doubles from (1.8 moles to moles) the rate of the reaction doubles (from 5 to 60 seconds). Also we can see that as the reaction continues the concentration of the reactants decrease and so does the rate of the reaction as we can see the decreasing gradient on the graph steadily falling and coming to a stop when the reaction is complete and the magnesium has completely disappeared.
Conclusion
I can conclude that if you double the concentration of the acid the reaction rate would also double, this is because the ions are closer together in a concentrated solution. The closer together they are, the more often the ions collide. The more often they collide, the higher the chance of a reaction between the magnesium and the hydrochloric acid. Also because there are more particles in the solution which would increase the likelihood that they would hit the magnesium so the reaction rate would increase. The graph gives us a good device to prove that if you double the concentration the rate of reaction doubles. If you increase the number of particles in the solution it is more likely that they will collide more often. In the reaction, when the magnesium hit the acid, it fizzed and produced many bubbles it was silver in colour (which is one of magnesiums physical properties silvery
white metallic element), the activation energy of a particle gets higher with heat, the particles which have to have the activation energy are those particles which are moving, in the case of magnesium and hydrochloric acid, it is the hydrochloric acid particles which have to have the activation energy because they are the ones that are moving and bombarding the magnesium particles to produce magnesium chloride. The graph for 1/time had the form of an s curve and it did have some relationship with the other graph.
Conclusion
The experiments made were very successful and we had managed to complete the experiment fully and fairly.
The fastest reaction made was with no water, 60 cm of sodium this sulphate and 10 cm acid. This reaction is very fast with a time average of 44.1 seconds. The slowest reaction made was with 50 cm of water, 10 cm of sodium thiosulphate and 10-cm acid. This reaction was very slow with a time of 4,4.5 minutes in average. But this average time has mainly been made with the one anomalous result in a certain reaction. The reaction was stopped at 61.46, but the reaction was still not finished. It seemed that the chemicals in the flask had only reacted halfway, then it just stopped reacting.
Evaluation
There are many reasons why our results for the 1/time graph did not prove the point that concentration~1/time, such as
1. When the reaction takes place bubbles of H are given off, which might stay around the magnesium, which therefore reduces the surface area of the magnesium and so the acid cannot react properly so this affects the results.
. We could have controlled factors in the investigation better (e.g. the stirring of the solution because if this is not done properly it can lead to incorrect results).
. Using larger concentrations of acid would give a bigger more accurate conclusion instead of just using 10ml test tubes use 1litre test tubes, this way graphs would be more spaced out and give an accurate form or curve.
Interpretation and Evaluation
In this experiment I found out that many different factors including; Concentration, Temperature and Surface Area affect the rate of reaction. For the experiment I found out that the higher the concentration of the acid the quicker it takes to dissolve the magnesium. I know this because the more acid molecules that is in the beaker there is more chance of a successful collision to take place. Another factor that I learned is that the rate is constantly changing during the reaction because as time goes on there are fewer acid molecules. There are fewer acid molecules because when the acid reacts the same particle cannot react again, so there are less to end with than there are to start with. As time goes on the number of acid particle decrease so there is less chance of a successful reaction to take place.
Before I started the experiment I made up a prediction. I predicted that the more concentrated the acid solution the faster the magnesium and hydrochloric acid will react. I thought that this would happen because when there are more acid particles in the test tube the more chance there is of a successful collision. I was right in my prediction but I did not predict that the rate of reaction slows down as time goes on which did happen in my experiment.
Improvements
The experiments were handled fairly but it could have been even more fair. Because The reaction was finished when the black cross on the pad dissapeared and this is only seen by the naked eye. With the whole class doing this with different eye types, there is no exact fairness in the experiment.
Fairness in this issue can be found by using devices such as a light sensor. The light sensor will pass through the flask, of were an reaction is taking place to a reciever. When the light sensor can not reach the reciever, the timing will be stopped automatically. This will bring fairness to experiments to test all similar to rate of reaction.
Variables
INDEPENDANT VARIABLE My independent variable is the concentration of the acid.
CONTROLLED VARIABLE My controlled variables are the temperature of the acid, the size of the surface area of the magnesium, the volume of the acid/water solution and the length of the magnesium strip.
DEPENDANT VARIABLE My dependant variables are the volume of the magnesium and the mass of the magnesium.
Apparatus
Stop Clock - Water -
Acid - Test Tube rack -
Test Tube - Magnesium -
Ruler - Scissors -
Beaker - Measuring Cylinder -
Safety
Safety is a very important part of this experiment as we are working with a corrosive chemical that is very dangerous. When carrying out the experiment, be sure to wear safety goggles as we are working with acid. When measuring out the different concentrations of acid, be careful not to spill it onto your hands or clothing.
Method
To begin with, set up all the apparatus in a safe position. Then make up the different concentrations of acid. To do this, add a quantity of water to the acid.
Water (cm) Acid (cm) Molarity Total (cm)
0 5 1 5
5 0 0.8 5
10 15 0.6 5
15 10 0.4 5
0 5 0. 5
Pour 5cm of each molarity of acid into a test tube. Then drop in a cm strip of magnesium. As soon as the magnesium strip drops, start the stop clock. When the magnesium is no longer visible, stop the stop clock and record the time. When the magnesium strip is dropped in a gas appears and it gives off a hissing noise. We can work out the name of this gas by solving a simple equation
Hydrogen Chloride + Magnesium = Magnesium Chloride + Hydrogen
HCL + Mg = MgCL + H
Or collect this gas and test it with the POP� test to identify it as Hydrogen.
Do this with each of the different molarities and repeat this again at least two more times to ensure that an accurate result is achieved.
BOILING TUBE
ACID OF DIFFERENT
MOLARITIES
MAGNESIUM
STRIP (CM)
BOILING TUBE
MAGNESIUM CHLORIDE
(THE MAGNESIUM HAS REACTED
WITH THE ACID AND HAS
DISSAPPEARED)
I will record the results in a table under the following headings
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1
0.8
0.6
0.4
0.
I will record the results in a graph under the following headings
T
I
M
E
(S
E
C)
MOLARITY OF SOLUTION
Prediction
I predict that the more concentrated the acid solution the faster the magnesium and hydrochloric acid will react. I think that this will happen because when there are more acid particles in the test tube the more chance there is of a successful collision
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. The particles in the liquid move around continually. Here an acid particle is about to collide with a magnesium atom.
. If the collision has enough energy, reaction takes place. Magnesium chloride and hydrogen are formed.
. If the collision does not have enough energy, no reaction occurs. The acid particle bounces away again.
Results
1st results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 5
0.8 5 6
0.6 5 11
0.4 5 516
0. 5 117
nd results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 4
0.8 5 40
0.6 5 6
0.4 5 67
0. 5 NO TIME
rd results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 6
0.8 5 8
0.6 5 61
0.4 5
0. 5 NO TIME
In some of the tests we had no time to complete them.
I also made a table for my average results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 5
0.8 5 8
0.6 5 85
0.4 5 8
0. 5 117
I only recorded this result once because we had only enough time to test it once.
Mind that the sample papers like Rates of reactions between HCL and magnesium ribbon presented are to be used for review only. In order to warn you and eliminate any plagiarism writing intentions, it is highly recommended not to use the essays in class. In cases you experience difficulties with essay writing in class and for in class use, order original papers with our expert writers. Cheap custom papers can be written from scratch for each customer that entrusts his or her academic success to our writing team. Order your unique assignment from the best custom writing services cheap and fast!
Rates of reactions between HCL and magnesium ribbon
Aim
I plan to investigate the effect of concentration of acid, in the reaction between dilute hydrochloric acid and magnesium ribbon. The rate of a chemical reaction is a measure of how fast the reaction takes place. It is important to know that a rapid reaction is completed in a short period of time. Some reactions are very fast, for example; the formation of silver chloride precipitates when silver nitrate and hydrochloric acid solutions are mixed. In this investigation I will test different concentrations of acid reacting with magnesium.
/Plan
To investigate what effect concentration of sodium thiosulphate has on the rate of reaction. The volume of HCL needs to be kept at 10cm constantly each time. Start with 60cm of sodium thiosulphate. Last reaction will have only 10cm of sodium thiosulphate.
Reactions will be completed when the x disappears, for the timing to stop. Three reactions will be made for each test; this is done to gain the different averages.
Introduction
I will be conducting an experiment on the rate of reaction for my GCSE coursework. I will be doing this coursework for a period of two weeks. We will be reacting sodium thiosulphate with hydrochloric acid. I will be investigating the effects had on rate of reaction.
When sodium thiosulphate and hydrochloric are mixed, a yellow precept of sulphur is produced. The solution becomes increasingly difficult to see through as more and more sulphur is formed.
Prediction
My prediction is that as the concentration of the hydrochloric acid increases, the time taken for the magnesium to disappear decreases. I predict that when the concentration of the hydrochloric acid doubles, the rate of the reaction doubles.
Background Knowledge
Rate is a measure of how fast or slow something is. For example, Silver Chloride precipitating (this is a very fast reaction) and Concrete setting (it may take a couple of days for concrete to harden). Rate is a measure of the change that happens in a single unit of time. Any suitable unit of time can be used - a second, a minute, an hour and even a day.
To find the rate of reaction, you should measure The amount of reactant used up per unit of time or the amount of a product produced per unit of time.
We are going to do an experiment on the rate of reaction. We are using acid and magnesium strips to test the rate of reaction.
Rates of reaction can be varied by a number of factors
? The concentration of the acid in which the magnesium is placed,
? The temperature of the acid and
? The size of the surface area of the magnesium strip.
Why rate changes with concentration If the concentration of the acid is increased, the reaction goes faster.
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. In dilute acid, there are not so many acid particles. This means there is not much chance of an acid particle hitting a magnesium atom.
. Here the acid is more concentrated - there are more acid particles in it. There is now more chance of a successful collision occurring.
The more successful collisions there are the faster the reaction.
This idea also explains why the reaction between magnesium and hydrochloric acid slows down as time goes on
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. At the start, there are plenty of magnesium atoms and acid particles. But they get used up during successful collisions.
. After a time, there are fewer magnesium atoms, and the acid is less concentrated. So the reaction slows down.
Why rate changes with the 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 of them are successful. Therefore the rate of reaction increases.
Why rate increases with surface area The reaction between the magnesium and acid is much faster when the metal is powdered
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. Acid particles can collide only with magnesium atoms on the outside of the metal.
. When the metal is powdered, many more atoms are exposed. So there is a greater chance of successful collisions.
For my experiment my independent variable will be the concentration of the acid. I chose this as my independent variable as I feel this is the safest and easiest way to carry out the experiment. If I was to choose the temperature of the acid as my independent variable, and if I were to heat the acid too much it may boil and produce a corrosive gas, which would life threatening. It would be difficult to work out an accurate reading of the surface area if I was to choose the surface area as my independent variable.
Linking prediction to theory
Reaction rate and concentration.
The collision theory describes how the rate of reaction increases (the time taken for the magnesium ribbon to disappear when it is reacted with hydrochloric acid) when the concentration of HCL increases. As the reaction continues, the concentration of the reacting substances decreases and so does the rate of reaction. The reaction is speeded up if the number of collisions is increased. The higher the concentration of HCL you use, the less time it takes for the magnesium to disappear and so the rate reaction increases. If the activation energy is high only a small amount of particles will have enough energy to react so the reaction rate would be very small, however the activation energy is very low the number of particles with that amount of energy would be so high, so start, so the reaction rate would be higher.
Apparatus
Hydrochloric acid( mole)
Water(to dilute acid)
10ml testube
magnesium(cm long)
stop clock(sensitivity 1/10s)
beaker
In order to conduct any type of experiment, you need equipment. The equipment I used was a
Measuring Cylinder
Small measuring cylinder
Flask
beakers
Pad (marked with black cross) white cross
Timer
Method
To get the amount of magnesium and the amount of hydrochloric acid to use in the situation, we have to use an excess of acid so that all of the magnesium disappears.
An equation for the reaction
Magnesium + hydrochloric acid magnesium chloride + hydrogen
Mg(s) + HCL(aq)Mgcl(aq) + H(g)
1mole moles 1mole 1mole
So we can say that one mole of magnesium reacts with moles of hydrochloric acid. Throughout the experiment, we diluted the acid solution using water, as we did this the concentration of the acid decreased. Then 8ml of acid and ml of water solution on the magnesium, measured time taken for magnesium to disappear using stop clock. Then 7ml of acid and ml of acid, repeated as above. This way the rate of reaction(the time taken for the magnesium to disappear) was measured accurately for a fair test.
Results
The results for the time taken for magnesium to disappear when it is placed in different concentrations of acid are summarised below.
Analysis of results
From the results in the table and the graph we can see a steady increase in the rate of reaction as the concentration of the acid decreases. This complies with my prediction. The graph shows that there is an increase in the rate of reaction as the concentration increases because the graph has its largest gradient or it is steepest at this point. When the graph was made into 1/time the result should have been a straight line graph but it did not turn out this way even though concentration~1/time. This 1/time graph could be wrong because of inaccurate results so there seems to be no relationship between the concentration graph and the 1/time graph. We can see from the rate of reaction graph that when the concentration roughly doubles from (1.8 moles to moles) the rate of the reaction doubles (from 5 to 60 seconds). Also we can see that as the reaction continues the concentration of the reactants decrease and so does the rate of the reaction as we can see the decreasing gradient on the graph steadily falling and coming to a stop when the reaction is complete and the magnesium has completely disappeared.
Conclusion
I can conclude that if you double the concentration of the acid the reaction rate would also double, this is because the ions are closer together in a concentrated solution. The closer together they are, the more often the ions collide. The more often they collide, the higher the chance of a reaction between the magnesium and the hydrochloric acid. Also because there are more particles in the solution which would increase the likelihood that they would hit the magnesium so the reaction rate would increase. The graph gives us a good device to prove that if you double the concentration the rate of reaction doubles. If you increase the number of particles in the solution it is more likely that they will collide more often. In the reaction, when the magnesium hit the acid, it fizzed and produced many bubbles it was silver in colour (which is one of magnesiums physical properties silvery
white metallic element), the activation energy of a particle gets higher with heat, the particles which have to have the activation energy are those particles which are moving, in the case of magnesium and hydrochloric acid, it is the hydrochloric acid particles which have to have the activation energy because they are the ones that are moving and bombarding the magnesium particles to produce magnesium chloride. The graph for 1/time had the form of an s curve and it did have some relationship with the other graph.
Conclusion
The experiments made were very successful and we had managed to complete the experiment fully and fairly.
The fastest reaction made was with no water, 60 cm of sodium this sulphate and 10 cm acid. This reaction is very fast with a time average of 44.1 seconds. The slowest reaction made was with 50 cm of water, 10 cm of sodium thiosulphate and 10-cm acid. This reaction was very slow with a time of 4,4.5 minutes in average. But this average time has mainly been made with the one anomalous result in a certain reaction. The reaction was stopped at 61.46, but the reaction was still not finished. It seemed that the chemicals in the flask had only reacted halfway, then it just stopped reacting.
Evaluation
There are many reasons why our results for the 1/time graph did not prove the point that concentration~1/time, such as
1. When the reaction takes place bubbles of H are given off, which might stay around the magnesium, which therefore reduces the surface area of the magnesium and so the acid cannot react properly so this affects the results.
. We could have controlled factors in the investigation better (e.g. the stirring of the solution because if this is not done properly it can lead to incorrect results).
. Using larger concentrations of acid would give a bigger more accurate conclusion instead of just using 10ml test tubes use 1litre test tubes, this way graphs would be more spaced out and give an accurate form or curve.
Interpretation and Evaluation
In this experiment I found out that many different factors including; Concentration, Temperature and Surface Area affect the rate of reaction. For the experiment I found out that the higher the concentration of the acid the quicker it takes to dissolve the magnesium. I know this because the more acid molecules that is in the beaker there is more chance of a successful collision to take place. Another factor that I learned is that the rate is constantly changing during the reaction because as time goes on there are fewer acid molecules. There are fewer acid molecules because when the acid reacts the same particle cannot react again, so there are less to end with than there are to start with. As time goes on the number of acid particle decrease so there is less chance of a successful reaction to take place.
Before I started the experiment I made up a prediction. I predicted that the more concentrated the acid solution the faster the magnesium and hydrochloric acid will react. I thought that this would happen because when there are more acid particles in the test tube the more chance there is of a successful collision. I was right in my prediction but I did not predict that the rate of reaction slows down as time goes on which did happen in my experiment.
Improvements
The experiments were handled fairly but it could have been even more fair. Because The reaction was finished when the black cross on the pad dissapeared and this is only seen by the naked eye. With the whole class doing this with different eye types, there is no exact fairness in the experiment.
Fairness in this issue can be found by using devices such as a light sensor. The light sensor will pass through the flask, of were an reaction is taking place to a reciever. When the light sensor can not reach the reciever, the timing will be stopped automatically. This will bring fairness to experiments to test all similar to rate of reaction.
Variables
INDEPENDANT VARIABLE My independent variable is the concentration of the acid.
CONTROLLED VARIABLE My controlled variables are the temperature of the acid, the size of the surface area of the magnesium, the volume of the acid/water solution and the length of the magnesium strip.
DEPENDANT VARIABLE My dependant variables are the volume of the magnesium and the mass of the magnesium.
Apparatus
Stop Clock - Water -
Acid - Test Tube rack -
Test Tube - Magnesium -
Ruler - Scissors -
Beaker - Measuring Cylinder -
Safety
Safety is a very important part of this experiment as we are working with a corrosive chemical that is very dangerous. When carrying out the experiment, be sure to wear safety goggles as we are working with acid. When measuring out the different concentrations of acid, be careful not to spill it onto your hands or clothing.
Method
To begin with, set up all the apparatus in a safe position. Then make up the different concentrations of acid. To do this, add a quantity of water to the acid.
Water (cm) Acid (cm) Molarity Total (cm)
0 5 1 5
5 0 0.8 5
10 15 0.6 5
15 10 0.4 5
0 5 0. 5
Pour 5cm of each molarity of acid into a test tube. Then drop in a cm strip of magnesium. As soon as the magnesium strip drops, start the stop clock. When the magnesium is no longer visible, stop the stop clock and record the time. When the magnesium strip is dropped in a gas appears and it gives off a hissing noise. We can work out the name of this gas by solving a simple equation
Hydrogen Chloride + Magnesium = Magnesium Chloride + Hydrogen
HCL + Mg = MgCL + H
Or collect this gas and test it with the POP� test to identify it as Hydrogen.
Do this with each of the different molarities and repeat this again at least two more times to ensure that an accurate result is achieved.
BOILING TUBE
ACID OF DIFFERENT
MOLARITIES
MAGNESIUM
STRIP (CM)
BOILING TUBE
MAGNESIUM CHLORIDE
(THE MAGNESIUM HAS REACTED
WITH THE ACID AND HAS
DISSAPPEARED)
I will record the results in a table under the following headings
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1
0.8
0.6
0.4
0.
I will record the results in a graph under the following headings
T
I
M
E
(S
E
C)
MOLARITY OF SOLUTION
Prediction
I predict that the more concentrated the acid solution the faster the magnesium and hydrochloric acid will react. I think that this will happen because when there are more acid particles in the test tube the more chance there is of a successful collision
1
- Acid Particle
- Water Molecule
- Magnesium Atoms
1. The particles in the liquid move around continually. Here an acid particle is about to collide with a magnesium atom.
. If the collision has enough energy, reaction takes place. Magnesium chloride and hydrogen are formed.
. If the collision does not have enough energy, no reaction occurs. The acid particle bounces away again.
Results
1st results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 5
0.8 5 6
0.6 5 11
0.4 5 516
0. 5 117
nd results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 4
0.8 5 40
0.6 5 6
0.4 5 67
0. 5 NO TIME
rd results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 6
0.8 5 8
0.6 5 61
0.4 5
0. 5 NO TIME
In some of the tests we had no time to complete them.
I also made a table for my average results;
Molarity Volume (cm) Size of
Magnesium (cm) Time Taken
(sec) Rate of Reaction
1 5 5
0.8 5 8
0.6 5 85
0.4 5 8
0. 5 117
I only recorded this result once because we had only enough time to test it once.
Mind that the sample papers like Rates of reactions between HCL and magnesium ribbon presented are to be used for review only. In order to warn you and eliminate any plagiarism writing intentions, it is highly recommended not to use the essays in class. In cases you experience difficulties with essay writing in class and for in class use, order original papers with our expert writers. Cheap custom papers can be written from scratch for each customer that entrusts his or her academic success to our writing team. Order your unique assignment from the best custom writing services cheap and fast!
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