Investigation into the Effect of Concentration on Rate of Reaction between Marble Chips and Acid Essay Example

Investigation into the Effect of Concentration on Rate of Reaction between Marble Chips and Acid Essay Before carrying out a set of experiments, I decided to do preliminary work to look at quantities and measurements, in order for my experiments to work smoothly and accurately. To do this, I tested both amounts of marble chips and amounts and concentration ranges of acid. I also experimented with different measuring cylinder sizes. I carried out a few simple experiments varying the above, and came up with the most sensible.We began by what seemed the most practical quantities. Firstly we looked at marble chips. We took 5g as a starting example. To accompany this we looked at what would be a sensible amount of liquid to accompany it and chose 50ml. To find the right measuring cylinder to use, we set up a mock experiment and began with a 25ml measuring cylinder. We timed experiments for both the strongest and weakest concentrations of acid and recorded the following results.50ml acid0ml water = 26.80 seconds10ml acid40ml water = 2 minutes, 53.77 secondsThese were both practical results and so we were happy with the size of the measuring cylinder. Along with this, we also took note at how our quantities of acid and marble chips worked together and saw that they were both satisfactory. All other equipment and the set up of the apparatus were also fine and so we decided to move on to the proper experiments.Planning My WorkFor this experiment I will need to investigate how the rate of reaction of marble chips is effected by acid as well as considering other factors that my have an effect.Aim: To find a relationship between the concentration of acid and the rate of which a reaction takes place with marble chips.To begin the experiment, I need to look at the chemistry of marble chips (calcium carbonate) and acid and so I will begin with their equations.Word equation:calcium carbonate + hydrochloric acid calcium chloride + water + carbon dioxideChemical equation:CaCo3(s) + 2HCl(aq) CaCl2(aq) + H2O(l) + CO2(g)When the reaction takes place, carbon dioxide, water and salt will be produced. Out of these three, I have chosen carbon dioxide as the one to measure for my rate of reaction. This is because it will be the easiest and most noticeable to collect. By the measurement of the carbon dioxide, we will be able to accurately follow how fast the reaction occurs. Pg 190 of the Chemistry for you book, shows a sensible, simple and accurate way of measuring a gas like carbon dioxide, in an upturned measuring cylinder filled with water. If we place marble chips and acid in a conical flask, the gas will bubble through a delivery tube lowering the level of water, which we will then be able to time until all water has left the cylinder.The amount of time it takes for the gas to fill the measuring cylinder will show us how much carbon dioxide has been given off and so will show us the rate of reaction. Rate of reaction is altered by three main things. One is SURFACE AREA. This will relate to the surface area of our marble chips. The finer the chips, the larger the surface area, and so the larger the rate of reaction. However, we are intending to keep the surface area the same. Another factor is TEMPERATURE. Again, we are not going to alter the temperature. If we were to, the hotter the temperature, the faster the rate of reaction as the molecules would have more energy. The other is CONCENTRATION. This relates to the concentration of the acid and is what we will use as our variable.The acid particles can only react with the marble chips when they collide, as seen in the diagrams.The acid particles move randomly through the water. As you increase the concentration of the acid, there are more acid particles in the same volume. Therefore there is a greater chance of acid particles colliding, and reacting, with particles on the surface of the marble and you increase the rate of reaction.This is what I will use in my experiment. The concentration of acid is written in Molars. For example, 1M (molar) is half the concentration of 2M. I will alt er the concentration to see what effect it has on the rate of reaction.Predictions:I predict that when investigation the effect of concentration on rate of reaction between marble chips and acid, that an alteration in concentration will effect the rate of reaction in a pattern. As has already been explained, as you increase the concentration of the acid, there are more acid particles in the same volume and so therefore there is a greater chance of acid particles colliding, and reacting, with particles on the surface of the marble. Because of this, I will make the prediction that the higher the concentration of acid, the faster the rate of reaction with the marble chips and the faster my measuring cylinder will fill with carbon dioxide.I also predict a more detailed pattern. I predict that the level of concentration may also have a direct effect on the rate of reaction. E.g. that if a 2M was compared with a 1M acid which is half the concentration, the rate of reaction will also be ha lf. I will now need to carry out my experiment to test these predictions.My ExperimentDiagram:Apparatus:Conical flask to hold the marble chips and acid for the experiment50ml measuring cylinder to measure the volume of acid being used in the experiment. I chose 50ml volume because that is the maximum acid we will need.Delivery tube and bung will transport C02 given offWeighing pot to hold the marble chips for weighing25ml measuring cylinder to collect the C02 given off by the experiment. I chose 25ml because it was the most sensible sizeBalance reading to 0.01g, must be accurate, to weigh the marble chipsWater trough to hold the water for the collection of C02Stop clock reading to 0.01 of a second, to accurately time the collection of C02 and the rate of the reactionMethod:Each time the variable is altered, I shall carry out exactly the same experiment, merely with a different concentration.* I will begin by collecting and setting up all my equipment. I need to make sure tha t the chonical flask is clean and doesnt have any substances already in it. The 25ml measuring cylinder needs to be filled with water. We found that if we filled a 25ml measuring cylinder, due to excess volume above the measurements, it actually held a total of 40ml. We found this by completely filling the cylinder as we would in the experiment, and then pouring this into a larger measuring cylinder and taking the reading. The cylinder then needs to be stood upside down in the trough that also needs to have an ample amount of water in. The delivery tube needs to be under the cylinder but does not yet need to have the bung in the flask.* The marble chips then need to be weighed accurately, remembering to take into account the surface area. These can then be put into the flask.* I will then prepare my acid to the right concentration. The amount of acid needs to be measured accurately in the separate, 50ml measuring cylinder and then water needs to be added, if required, to dilute the acid to the right concentration.* The acid can then be added to the flask and marble chips. The bung needs to be put in the flask immediately, and as soon as this is done I will begin the stop clock.* I will then watch the flask carefully and as soon as the first bubble comes out of the measuring cylinder, will stop the stop clock and take my reading.This will be carried out for each experiment. In-between, it is important to rinse and dry the chonical flask and to refill the 25ml measuring cylinder.After obtaining a complete set of results, I will then go through the process again to repeat my experiments. This will give me added information and will help explain anything out of place if necessary.Concentrations and Readings:I am going to carryout five experiments, and then repeat these to give me a total of 10 results, two for each experiment. The experiments I will carry out will be of five different concentrations of acid. Along with the concentrations in ml of both acid and wat er, I have written along with it the concentrations in molar (M). (Our original strength of acid is 2M) The concentrations will be:Acid (ml)Water (ml)CalculationMolar (M)5002 x 5/5 = M240102 x 4/5 = M1.630202 x 3/5 = M1.220102 x 2/5 = M0.810402 x 1/5 = M0.4We see that in this experiment, 2M will be the strongest acid, 0.4 will be the weakest. The way that the amount of ml is always equal to 50ml means though the concentrations change, the volume of liquid will be kept the same.Fair Test:It is very important to make my experiment fair. If it is not kept exact, then my results may easily be altered by slight differences that shouldnt occur.In order to keep my experiment fair, I will ensure that there is only one variable at any time. My variable will be the concentration of acid to water. Other possible variables such as the amount of liquid, temperature, amount of marble chips or surface area of marble chips should never change and should always stay the same. To do this, we will kee p the volume of liquid the same by measuring accurately in an accurate measuring cylinder. The amount of marble chips will be kept same by weighing them on accurate weighing scales. The surface area of the chips will be harder to keep accurate. We can do this generally by attempting to keep the marble chips of similar sizes as accurately as possible. I have decided to use small marble chips rather than large so that the surface areas are more similar. However, this may not always be completely accurate, and so we will have to take this into account and remember this when looking at results. We will monitor temperature with a thermometer, but will work to room temperature. We will not be able to alter the temperature as we please, and so will take a note of the temperatures for each experiment so that we can explain any changes of patterns in our results.It is also important not to change apparatus or equipment and to keep the experiment exactly the same.If this is kept to then my ex periment will be fair, hopefully giving me the most accurate results as possible.Safe Test:Keeping a safe test is also very important for the safety of me and other people around me. To ensure that my experiment is safe, I will carry out the following precautions.* Goggles should be warn to protect my eyes from acid or in case another accident occurred* I should act in a sensible and safe manner, carefully working with the equipment and being aware of any dangers.* The low concentration of acid I will use is a safety precaution to ensure that the acid is not dangerous.Obtaining My EvidenceTo obtain my evidence, I began by setting up my equipment and following the plan previously written. I measured hydrochloric acid (HCl) with water to produce the 50ml volume of the desired concentration, and added to this, 5g of small marble chips. I timed, in seconds, how long this took to produce a 45ml3 of gas by bubbling it through a delivery tube into an upturned mea-suring cylinder of water. The volume of which was 45ml. (All this is explained in more detailed in my plan). I included certain apparatus for accuracy. The reaction was timed accurately by using a stop clock measuring to 100th of a second. The scales measured the marble accurately by measuring exact to 0.01g. This accuracy of this was also improved by using small marble chips with more similar surface areas. The measuring cylinders used all measured to 0.1ml.From carrying out this process, I produced a set of results for 5 concentrations of acid, 2M, 1.6M, 1.2M, 0.8M and 0.4M. I then repeated these results for even more accuracy so that I will be able to produce an average.Results:The results for both the first set of experiments and the repeated, second set of experiments have been combined into one table. The column of Concentration, is measured in Molars (M). This is the volume of hydrochloric acid (HCl) and water (both measured in cm3) shown together. Time 1 and Time 2 are the times (in seconds) for expe riment 1, and the repeats, experiment 2.Other information that I also took, was a note of the room temperature at the time of taking the results. The results of experiment 1 and experiment two were taken on different days and so this was important information. I already know that temperature is an altering factor in rate of reaction and so if the temperature if not the same then it is important to know so that a change in results can be explained.Experiment 1 temperature 200CExperiment 2 temperature 190CThe first lots of experiments were taken at a temperature 10C higher than the second lot of experiments. This needs to be known to explain any patterns that may be related.Table of My Results:HCl (cm3)Water (cm3)Concentration (Molar)Time 1 (seconds)Time 2 (seconds)500213.0113.0740101.617.2713.3030201.227.3022.5120300.844.3732.4910400.4215.12186.22Analysing My Evidence and Drawing ConclusionsFrom my table of results, I can calculate additional information. I can work out an average ti me by adding the two existing times and dividing them by two. I can then find a rate of each reaction by dividing 1 by the average time. This will give me another pattern to follow by showing me how fast the reaction went at the different concentrations. The formulas for these are:Average = time + time / 2Reaction = 1 / timeI am going to add the answers of these as additional columns onto my table.HCl (cm3)Water (cm3)Concentration (Molar)Time 1 (seconds)Time 2 (seconds)Average Time (seconds)Rate500213.0113.0713.040.76740101.617.2713.3015.290.06530201.227.3022.5125.310.0420300.844.3732.4938.430.02610400.4215.12186.22200.670.005From the table, without the average time, we can see a common difference between the time in experiment one and the time in experiment two. All results for experiment 1 are slightly quicker than the times for experiment two (with exception of the 2M experiment). We can relate this back to the temperature difference. Temperature affects the rate of reaction. Whe n particles are heated up, they have more energy. They move around more quickly. As they travel faster, there are more collisions in a certain time. As well as this, with more energy, more collisions are likely to result in a reaction. Therefore, as temperatures are raised, reactions get faster and more likely, increasing the rate of reaction.I noted when obtaining my results how the room temperature at the time experiment 1 was being carried out was 200C, where as experiment 2 was at 190C. This means that experiment 1, having the higher temperature, would have shown a faster rate of reaction, which is exactly what is shown in the table.This is apart from the reading for the highest concentration, the 2M experiment. Here we see that the time in experiment 2 is faster than that in experiemnt1. However, this is by 0.06 of a second. Here human reaction time may be a factor. Although the stop clocks are very accurate, they will never be exact, as it is very hard to stop the clock exactl y at the time you want it to. This error may have led to this small difference. By noticing this here, we can also take it into account for the other experiments, remembering that they are not exact but only by a very small error.The average helps to even out the differing results which means that one, middle number is produced to work with. Because, also, I have no obvious anomalous results, readings that dont fit the pattern of the higher the concentration, the faster the reaction and so the shorter the time, the averages will follow the same trend.To look more closely at my data, I am going to enter my average times onto a line graph. I think this is the best type of graph to use as it fits my results of continuous date and will show any trends clearly. This is on the next page (graph 1). The concentration in molars is along the x-axis, the time of the reaction in seconds is along the y-axis. I have plotted my recorded points and drawn a curved line of best fit.From this data I c an now say that the concentration does effect the rate of reaction. The line of best fit shows very clearly, a definite trend that as you increase the concentration, you decrease the time taken, showing an increase in speed. Rate and time are inversely related. As one increases the other decreases, as seen on the graph, meaning that as time increases, rate of reaction decreases.What we see on the graph is a sharp decrease from about 200 seconds to about 50 seconds over a concentration range of only 0.3M showing fast reactions. Over another 11M there is a much more gradual decrease as it slows down, only covering approximately a range of 49 seconds. The remaining range of 2M covers 1 second and appears to be reaching a level line.The second graph (graph 2 over the page), again a line graph, is using the rate I worked out in the table, against the concentration. This gives us I more direct trend towards the effect of concentration on rate of reaction. It shows very definitely and clea rly that the higher the concentration, the higher the rate. As rate and time are inverse, I would expect an almost mirror of the concentration against time graph. This is what has happened. Instead of a sharp decrease followed by a gradual decrease as seen in the concentration against time graph, the concentration against rate graph shows a gradual increase followed by a sharp increase. My line of best fit covers 1.4M at a 0.05 rate very gradually, then a slight increase, and then over 1M, the rate increases by 0.567.My prediction before carrying out this experiment was that the higher the concentration of acid, the faster the rate of reaction. Both these graphs prove this to be correct. This is due to the activity of the molecules in the experiment. The rate of reaction is the amount of a substance that takes part in a chemical reaction in a given time. In order to react, the particles must collide with each other. If the rate of reaction is increasing, it is the amount of particle s colliding and therefore reacting that is increasing. As we increase the concentration of acid, the substance taking part in the chemical reaction (along with marble chips), the rate of reaction increases. This is because an increase in concentration increases the amount of collisions taking place. With more particles in the same volume, there is a greater and more common likely hood of collisions taking place. This is why concentration effects rate of reaction.The second part of my prediction was more detailed. I predicted that the level of concentration may also have a direct effect on the rate of reaction, meaning that if the reaction of a 2M acid was compared with that of a 1M acid, which is half the concentration, the rate of reaction will also be half.I looked at my graph of concentration against rate to investigate this. I used the examples of 1M and 2M and took the following readings of my graph and line of best fit.1M = rate of 0.032M = rate of 0.72This shows my prediction to be very incorrect. If it would be true, then my graph would show a straight line of equal increase. However, my line of best fit gradually increases, going against my prediction.From my results I can conclude that the rate of reaction between marble chips and acid is increased by an increase in concentration.EvaluationLooking back on the experiment, I think that I have carried out successful, dependable procedure that has given me precise and reliable evidence and results. First I will look at the practical work that I did. When doing the practical work, I followed my plan accurately. I kept it a safe and fair test and this is important. I experiment I planned was easy to carry out. Problems arose in temperature. The only variable was meant to be concentration, but due to uncontrollable circumstances, room temperature did alter. Luckily this occurred between sets of experiments which gave me additional information to look into. However, if that had happen part way through a set of results my results may have been slightly more irregular. To overcome this problem, results could have been taken all in one go. However, this was not practical in the spaces of time we were able to have. The other variable of surface area appeared to de successful. We already took precautions over this by using small marble chips instead of large, and so no problems arose.The accuracy of my results is as accurate as I think I would need. From my results I have produced graphs that show very definite and visible trends and patterns and no anomalous results and so the readings must have been correct. It may be possible to improve accuracy. I learnt from the strongest concentration, the 2M acid and the fastest reaction, that for short spaces of time the accuracy is not as exact. This could be solved by an alteration in equipment. If I were to do the experiment again, I would use a larger upturned measuring cylinder. The one I used held 45ml3 of solution. I found this took roughly 1 3 seconds to fill with gas, making it slightly inaccurate because it was a small space of time. However, if we increase the volume of the cylinder, it would take a longer time period. This may have improved accuracy. Other equipment all proved fine. I had no troubles with any other pieces of apparatus and would not alter them.To look into this investigation further of how concentration alters rate of reaction, I would like to look into concentration of solids in a reaction and concentrations of gases, similar to how we look at concentration of liquid and acid. It will be interesting to see if gases for instance have the same reaction patterns as liquids. I can see that my results mean that an increase of concentration of acid increases the rate. Would an increase of concentration of gas make any difference in the rate of reaction? This would help to add to an overall conclusion to the investigation. Investigation into the Effect of Concentration on Rate of Reaction between Marble Chips and Acid Essay Example Investigation into the Effect of Concentration on Rate of Reaction between Marble Chips and Acid Essay Before carrying out a set of experiments, I decided to do preliminary work to look at quantities and measurements, in order for my experiments to work smoothly and accurately. To do this, I tested both amounts of marble chips and amounts and concentration ranges of acid. I also experimented with different measuring cylinder sizes. I carried out a few simple experiments varying the above, and came up with the most sensible.We began by what seemed the most practical quantities. Firstly we looked at marble chips. We took 5g as a starting example. To accompany this we looked at what would be a sensible amount of liquid to accompany it and chose 50ml. To find the right measuring cylinder to use, we set up a mock experiment and began with a 25ml measuring cylinder. We timed experiments for both the strongest and weakest concentrations of acid and recorded the following results.50ml acid0ml water = 26.80 seconds10ml acid40ml water = 2 minutes, 53.77 secondsThese were both practical results and so we were happy with the size of the measuring cylinder. Along with this, we also took note at how our quantities of acid and marble chips worked together and saw that they were both satisfactory. All other equipment and the set up of the apparatus were also fine and so we decided to move on to the proper experiments.Planning My WorkFor this experiment I will need to investigate how the rate of reaction of marble chips is effected by acid as well as considering other factors that my have an effect.Aim: To find a relationship between the concentration of acid and the rate of which a reaction takes place with marble chips.To begin the experiment, I need to look at the chemistry of marble chips (calcium carbonate) and acid and so I will begin with their equations.Word equation:calcium carbonate + hydrochloric acid calcium chloride + water + carbon dioxideChemical equation:CaCo3(s) + 2HCl(aq) CaCl2(aq) + H2O(l) + CO2(g)When the reaction takes place, carbon dioxide, water and salt will be produced. Out of these three, I have chosen carbon dioxide as the one to measure for my rate of reaction. This is because it will be the easiest and most noticeable to collect. By the measurement of the carbon dioxide, we will be able to accurately follow how fast the reaction occurs. Pg 190 of the Chemistry for you book, shows a sensible, simple and accurate way of measuring a gas like carbon dioxide, in an upturned measuring cylinder filled with water. If we place marble chips and acid in a conical flask, the gas will bubble through a delivery tube lowering the level of water, which we will then be able to time until all water has left the cylinder.The amount of time it takes for the gas to fill the measuring cylinder will show us how much carbon dioxide has been given off and so will show us the rate of reaction. Rate of reaction is altered by three main things. One is SURFACE AREA. This will relate to the surface area of our marble chips. The finer the chips, the larger the surface area, and so the larger the rate of reaction. However, we are intending to keep the surface area the same. Another factor is TEMPERATURE. Again, we are not going to alter the temperature. If we were to, the hotter the temperature, the faster the rate of reaction as the molecules would have more energy. The other is CONCENTRATION. This relates to the concentration of the acid and is what we will use as our variable.The acid particles can only react with the marble chips when they collide, as seen in the diagrams.The acid particles move randomly through the water. As you increase the concentration of the acid, there are more acid particles in the same volume. Therefore there is a greater chance of acid particles colliding, and reacting, with particles on the surface of the marble and you increase the rate of reaction.This is what I will use in my experiment. The concentration of acid is written in Molars. For example, 1M (molar) is half the concentration of 2M. I will alt er the concentration to see what effect it has on the rate of reaction.Predictions:I predict that when investigation the effect of concentration on rate of reaction between marble chips and acid, that an alteration in concentration will effect the rate of reaction in a pattern. As has already been explained, as you increase the concentration of the acid, there are more acid particles in the same volume and so therefore there is a greater chance of acid particles colliding, and reacting, with particles on the surface of the marble. Because of this, I will make the prediction that the higher the concentration of acid, the faster the rate of reaction with the marble chips and the faster my measuring cylinder will fill with carbon dioxide.I also predict a more detailed pattern. I predict that the level of concentration may also have a direct effect on the rate of reaction. E.g. that if a 2M was compared with a 1M acid which is half the concentration, the rate of reaction will also be ha lf. I will now need to carry out my experiment to test these predictions.My ExperimentDiagram:Apparatus:Conical flask to hold the marble chips and acid for the experiment50ml measuring cylinder to measure the volume of acid being used in the experiment. I chose 50ml volume because that is the maximum acid we will need.Delivery tube and bung will transport C02 given offWeighing pot to hold the marble chips for weighing25ml measuring cylinder to collect the C02 given off by the experiment. I chose 25ml because it was the most sensible sizeBalance reading to 0.01g, must be accurate, to weigh the marble chipsWater trough to hold the water for the collection of C02Stop clock reading to 0.01 of a second, to accurately time the collection of C02 and the rate of the reactionMethod:Each time the variable is altered, I shall carry out exactly the same experiment, merely with a different concentration.* I will begin by collecting and setting up all my equipment. I need to make sure tha t the chonical flask is clean and doesnt have any substances already in it. The 25ml measuring cylinder needs to be filled with water. We found that if we filled a 25ml measuring cylinder, due to excess volume above the measurements, it actually held a total of 40ml. We found this by completely filling the cylinder as we would in the experiment, and then pouring this into a larger measuring cylinder and taking the reading. The cylinder then needs to be stood upside down in the trough that also needs to have an ample amount of water in. The delivery tube needs to be under the cylinder but does not yet need to have the bung in the flask.* The marble chips then need to be weighed accurately, remembering to take into account the surface area. These can then be put into the flask.* I will then prepare my acid to the right concentration. The amount of acid needs to be measured accurately in the separate, 50ml measuring cylinder and then water needs to be added, if required, to dilute the acid to the right concentration.* The acid can then be added to the flask and marble chips. The bung needs to be put in the flask immediately, and as soon as this is done I will begin the stop clock.* I will then watch the flask carefully and as soon as the first bubble comes out of the measuring cylinder, will stop the stop clock and take my reading.This will be carried out for each experiment. In-between, it is important to rinse and dry the chonical flask and to refill the 25ml measuring cylinder.After obtaining a complete set of results, I will then go through the process again to repeat my experiments. This will give me added information and will help explain anything out of place if necessary.Concentrations and Readings:I am going to carryout five experiments, and then repeat these to give me a total of 10 results, two for each experiment. The experiments I will carry out will be of five different concentrations of acid. Along with the concentrations in ml of both acid and wat er, I have written along with it the concentrations in molar (M). (Our original strength of acid is 2M) The concentrations will be:Acid (ml)Water (ml)CalculationMolar (M)5002 x 5/5 = M240102 x 4/5 = M1.630202 x 3/5 = M1.220102 x 2/5 = M0.810402 x 1/5 = M0.4We see that in this experiment, 2M will be the strongest acid, 0.4 will be the weakest. The way that the amount of ml is always equal to 50ml means though the concentrations change, the volume of liquid will be kept the same.Fair Test:It is very important to make my experiment fair. If it is not kept exact, then my results may easily be altered by slight differences that shouldnt occur.In order to keep my experiment fair, I will ensure that there is only one variable at any time. My variable will be the concentration of acid to water. Other possible variables such as the amount of liquid, temperature, amount of marble chips or surface area of marble chips should never change and should always stay the same. To do this, we will kee p the volume of liquid the same by measuring accurately in an accurate measuring cylinder. The amount of marble chips will be kept same by weighing them on accurate weighing scales. The surface area of the chips will be harder to keep accurate. We can do this generally by attempting to keep the marble chips of similar sizes as accurately as possible. I have decided to use small marble chips rather than large so that the surface areas are more similar. However, this may not always be completely accurate, and so we will have to take this into account and remember this when looking at results. We will monitor temperature with a thermometer, but will work to room temperature. We will not be able to alter the temperature as we please, and so will take a note of the temperatures for each experiment so that we can explain any changes of patterns in our results.It is also important not to change apparatus or equipment and to keep the experiment exactly the same.If this is kept to then my ex periment will be fair, hopefully giving me the most accurate results as possible.Safe Test:Keeping a safe test is also very important for the safety of me and other people around me. To ensure that my experiment is safe, I will carry out the following precautions.* Goggles should be warn to protect my eyes from acid or in case another accident occurred* I should act in a sensible and safe manner, carefully working with the equipment and being aware of any dangers.* The low concentration of acid I will use is a safety precaution to ensure that the acid is not dangerous.Obtaining My EvidenceTo obtain my evidence, I began by setting up my equipment and following the plan previously written. I measured hydrochloric acid (HCl) with water to produce the 50ml volume of the desired concentration, and added to this, 5g of small marble chips. I timed, in seconds, how long this took to produce a 45ml3 of gas by bubbling it through a delivery tube into an upturned mea-suring cylinder of water. The volume of which was 45ml. (All this is explained in more detailed in my plan). I included certain apparatus for accuracy. The reaction was timed accurately by using a stop clock measuring to 100th of a second. The scales measured the marble accurately by measuring exact to 0.01g. This accuracy of this was also improved by using small marble chips with more similar surface areas. The measuring cylinders used all measured to 0.1ml.From carrying out this process, I produced a set of results for 5 concentrations of acid, 2M, 1.6M, 1.2M, 0.8M and 0.4M. I then repeated these results for even more accuracy so that I will be able to produce an average.Results:The results for both the first set of experiments and the repeated, second set of experiments have been combined into one table. The column of Concentration, is measured in Molars (M). This is the volume of hydrochloric acid (HCl) and water (both measured in cm3) shown together. Time 1 and Time 2 are the times (in seconds) for expe riment 1, and the repeats, experiment 2.Other information that I also took, was a note of the room temperature at the time of taking the results. The results of experiment 1 and experiment two were taken on different days and so this was important information. I already know that temperature is an altering factor in rate of reaction and so if the temperature if not the same then it is important to know so that a change in results can be explained.Experiment 1 temperature 200CExperiment 2 temperature 190CThe first lots of experiments were taken at a temperature 10C higher than the second lot of experiments. This needs to be known to explain any patterns that may be related.Table of My Results:HCl (cm3)Water (cm3)Concentration (Molar)Time 1 (seconds)Time 2 (seconds)500213.0113.0740101.617.2713.3030201.227.3022.5120300.844.3732.4910400.4215.12186.22Analysing My Evidence and Drawing ConclusionsFrom my table of results, I can calculate additional information. I can work out an average ti me by adding the two existing times and dividing them by two. I can then find a rate of each reaction by dividing 1 by the average time. This will give me another pattern to follow by showing me how fast the reaction went at the different concentrations. The formulas for these are:Average = time + time / 2Reaction = 1 / timeI am going to add the answers of these as additional columns onto my table.HCl (cm3)Water (cm3)Concentration (Molar)Time 1 (seconds)Time 2 (seconds)Average Time (seconds)Rate500213.0113.0713.040.76740101.617.2713.3015.290.06530201.227.3022.5125.310.0420300.844.3732.4938.430.02610400.4215.12186.22200.670.005From the table, without the average time, we can see a common difference between the time in experiment one and the time in experiment two. All results for experiment 1 are slightly quicker than the times for experiment two (with exception of the 2M experiment). We can relate this back to the temperature difference. Temperature affects the rate of reaction. Whe n particles are heated up, they have more energy. They move around more quickly. As they travel faster, there are more collisions in a certain time. As well as this, with more energy, more collisions are likely to result in a reaction. Therefore, as temperatures are raised, reactions get faster and more likely, increasing the rate of reaction.I noted when obtaining my results how the room temperature at the time experiment 1 was being carried out was 200C, where as experiment 2 was at 190C. This means that experiment 1, having the higher temperature, would have shown a faster rate of reaction, which is exactly what is shown in the table.This is apart from the reading for the highest concentration, the 2M experiment. Here we see that the time in experiment 2 is faster than that in experiemnt1. However, this is by 0.06 of a second. Here human reaction time may be a factor. Although the stop clocks are very accurate, they will never be exact, as it is very hard to stop the clock exactl y at the time you want it to. This error may have led to this small difference. By noticing this here, we can also take it into account for the other experiments, remembering that they are not exact but only by a very small error.The average helps to even out the differing results which means that one, middle number is produced to work with. Because, also, I have no obvious anomalous results, readings that dont fit the pattern of the higher the concentration, the faster the reaction and so the shorter the time, the averages will follow the same trend.To look more closely at my data, I am going to enter my average times onto a line graph. I think this is the best type of graph to use as it fits my results of continuous date and will show any trends clearly. This is on the next page (graph 1). The concentration in molars is along the x-axis, the time of the reaction in seconds is along the y-axis. I have plotted my recorded points and drawn a curved line of best fit.From this data I c an now say that the concentration does effect the rate of reaction. The line of best fit shows very clearly, a definite trend that as you increase the concentration, you decrease the time taken, showing an increase in speed. Rate and time are inversely related. As one increases the other decreases, as seen on the graph, meaning that as time increases, rate of reaction decreases.What we see on the graph is a sharp decrease from about 200 seconds to about 50 seconds over a concentration range of only 0.3M showing fast reactions. Over another 11M there is a much more gradual decrease as it slows down, only covering approximately a range of 49 seconds. The remaining range of 2M covers 1 second and appears to be reaching a level line.The second graph (graph 2 over the page), again a line graph, is using the rate I worked out in the table, against the concentration. This gives us I more direct trend towards the effect of concentration on rate of reaction. It shows very definitely and clea rly that the higher the concentration, the higher the rate. As rate and time are inverse, I would expect an almost mirror of the concentration against time graph. This is what has happened. Instead of a sharp decrease followed by a gradual decrease as seen in the concentration against time graph, the concentration against rate graph shows a gradual increase followed by a sharp increase. My line of best fit covers 1.4M at a 0.05 rate very gradually, then a slight increase, and then over 1M, the rate increases by 0.567.My prediction before carrying out this experiment was that the higher the concentration of acid, the faster the rate of reaction. Both these graphs prove this to be correct. This is due to the activity of the molecules in the experiment. The rate of reaction is the amount of a substance that takes part in a chemical reaction in a given time. In order to react, the particles must collide with each other. If the rate of reaction is increasing, it is the amount of particle s colliding and therefore reacting that is increasing. As we increase the concentration of acid, the substance taking part in the chemical reaction (along with marble chips), the rate of reaction increases. This is because an increase in concentration increases the amount of collisions taking place. With more particles in the same volume, there is a greater and more common likely hood of collisions taking place. This is why concentration effects rate of reaction.The second part of my prediction was more detailed. I predicted that the level of concentration may also have a direct effect on the rate of reaction, meaning that if the reaction of a 2M acid was compared with that of a 1M acid, which is half the concentration, the rate of reaction will also be half.I looked at my graph of concentration against rate to investigate this. I used the examples of 1M and 2M and took the following readings of my graph and line of best fit.1M = rate of 0.032M = rate of 0.72This shows my prediction to be very incorrect. If it would be true, then my graph would show a straight line of equal increase. However, my line of best fit gradually increases, going against my prediction.From my results I can conclude that the rate of reaction between marble chips and acid is increased by an increase in concentration.EvaluationLooking back on the experiment, I think that I have carried out successful, dependable procedure that has given me precise and reliable evidence and results. First I will look at the practical work that I did. When doing the practical work, I followed my plan accurately. I kept it a safe and fair test and this is important. I experiment I planned was easy to carry out. Problems arose in temperature. The only variable was meant to be concentration, but due to uncontrollable circumstances, room temperature did alter. Luckily this occurred between sets of experiments which gave me additional information to look into. However, if that had happen part way through a set of results my results may have been slightly more irregular. To overcome this problem, results could have been taken all in one go. However, this was not practical in the spaces of time we were able to have. The other variable of surface area appeared to de successful. We already took precautions over this by using small marble chips instead of large, and so no problems arose.The accuracy of my results is as accurate as I think I would need. From my results I have produced graphs that show very definite and visible trends and patterns and no anomalous results and so the readings must have been correct. It may be possible to improve accuracy. I learnt from the strongest concentration, the 2M acid and the fastest reaction, that for short spaces of time the accuracy is not as exact. This could be solved by an alteration in equipment. If I were to do the experiment again, I would use a larger upturned measuring cylinder. The one I used held 45ml3 of solution. I found this took roughly 1 3 seconds to fill with gas, making it slightly inaccurate because it was a small space of time. However, if we increase the volume of the cylinder, it would take a longer time period. This may have improved accuracy. Other equipment all proved fine. I had no troubles with any other pieces of apparatus and would not alter them.To look into this investigation further of how concentration alters rate of reaction, I would like to look into concentration of solids in a reaction and concentrations of gases, similar to how we look at concentration of liquid and acid. It will be interesting to see if gases for instance have the same reaction patterns as liquids. I can see that my results mean that an increase of concentration of acid increases the rate. Would an increase of concentration of gas make any difference in the rate of reaction? This would help to add to an overall conclusion to the investigation.

How do Thomas Hardy and F Scott Fitzgerald present the issue of womens choices in The Melancholy Hussar and The Ice Palace Essay Example

How do Thomas Hardy and F Scott Fitzgerald present the issue of womens choices in The Melancholy Hussar and The Ice Palace Essay Example How do Thomas Hardy and F Scott Fitzgerald present the issue of womens choices in The Melancholy Hussar and The Ice Palace Paper How do Thomas Hardy and F Scott Fitzgerald present the issue of womens choices in The Melancholy Hussar and The Ice Palace Paper Essay Topic: Literature Short Stories of F Scott Fitzgerald The two short stories, which are going to be considered, were set over a hundred years apart. Both stories concern the subject of womens choices and were written by men. The Melancholy Hussar written by Thomas Hardy was set in the first years of the nineteenth century although it was written around 1875. The main character in this story is Phyllis who lives with her father on the South Coast of England. Parallel to this is the short story of The Ice Palace written by F.Scott Fitzgerald. This was written in 1919 about contemporary times. The Ice Palace is set in the Southern states of North America which is a totally different continent to that of The Melancholy Hussar. This helps to demonstrate the different social groups and influences. The first short story, by Thomas Hardy, is about a young girl named Phyllis. Phyllis lives with her father on the South Coast and is not very social and is restricted due to her relationship with her father. Phylliss father is not the sociable type and prefers to keep himself away, because of this he feels Phyllis should act in the same way. beyond the seclusion of the girl lay the seclusion of the father The Melancholy Hussar is set along the South coast. Thomas Hardy presents a quiet village in his introduction to the story. He explains the atmosphere first and a field is being described. The scenery is described as sombre and lifeless until the meaning of the scenery is introduced as symbolic. The scenery relates back to ninety years ago when the Kings German Legion slept there in tents. The main subject of the story is about Phyllis meeting a soldier and seeing him regularly. A good relationship was built up while Humphrey Gould, Phyllis fiance, is away. The story concerns love and when all the soldiers visit Phyllis is interested. She finds a soldier and begins talking to him. They meet every night at the same time until her father tries to send her to her aunts house. After a while Mattheus Tina, the German Hussar decides to run away as he does not like England. He wants to take Phyllis with him. you go with mebe my wife there Phyllis main decision is when she decides to join him. Phyllis sees that running away with Matthaus is a way of escaping her dull life. Daringly she risks her life and decides to change everything. Phyllis would not be able to return to her current life if she ran away as her father would be disgusted and embarrassed. Everything is planned and the night eventually arrives when Phyllis is just about to run over to Matthaus and a coach pulls up. It happens to be Humphrey and he talks about a present he is going to give to her for treating her badly. At this point Phyllis reverses her decision and decides to stay. Phyllis thinks to her self that she should stay and suffer for the rest of her life. She would stay at homemarry him, and suffer It is terrible to think that a woman would rather lead a suffering life for security than to run away to be with whom she wanted. Society as a whole was cruel to women and they did not have the status which women have today. Men were of a higher class than women and women had to be married to be respected. This was not always the case but in The Melancholy Hussar Phyllis is happy to be engaged so she can be accepted in the village. In a way Phyllis made the correct decision because that night her lover, Matthaus Tina, and his friend, Christoph Bless, are caught and are killed. Phyllis watches their killing for desertion and sinks down into her garden. Phyllis does not have a happy life, and although Humphrey has bought her a present he asks her to break off their engagement as he has already met somebody else. Phyllis does this as if a man breaks off an engagement it is considered rude and impolite. The Ice Palace however is a story on the same subject, womens choices, as the Melancholy Hussar and is about a young girl called Sally Carrol who is around the age of nineteen. The language style written by F.Scott Fitzgerald introduces this character after setting the scenery of a languid town. The sunlight dripped over the house like golden paint Each sentence is stringed together by words suggesting quietness and laziness and the description and F.Scott Fitzgerald sets the scene perfectly for a nice romantic story. Sally Carrol is middle class and lives in a family house, she is painting when first introduced, painting for her sister and when she kicks over a paint jar leaves it lying on the floor while preparing to go swimming with her best friends. kicked over the painting waterbut let it lay From the quotation above Sally Carrol is suggesting that she has a maid to tidy the house. From the general language style the South is portrayed a family orientated and the houses named after the families show this. The Butterworth, Larkin and Happer houses are the three mentioned and only the Happer house, of which Sally Carrol lives, is in view of the sun. The way in which Fitzgerald has written the story makes it easy reading and concentration is not needed as there are long flowing sentences to help the description nicely and also the main character, Sally Carrol, is convincing. She is portrayed as down to earth and human by the way in which she acts when around her friends. It is clear to see from the choices that Sally Carrol has to make that she is from a middle class setting from the 1920s. When Fitzgerald describes the North, he uses harsher language and short, sharper sentences. The flow of language is faster and more intense. F.Scott Fitzgerald uses the sentences and the language to create the atmosphere and pace of the story. The first sentence of the second part of the story introduces Harry Bellamy. Harry Bellamy, tall, broad and brisk From the quotation above it shows that short and sharper words can create pace and a new atmosphere. Whenever Harry Bellamy, Sally Carrols fiance, is spoken about, the short and quick pace is brought back to the writing and it is easy to distinguish that Harry Bellamy is not from the laid back Southern Georgia like Sally Carrol. Sally Carrol wants to go to places and to meet people and to do this she has made the decision that she is going to go to the North and live with a man whom she met in the summer. This was a hard decision for Sally Carrol but as stated in the text, she wants to make something of her life. I want to go places and see people and tied down herefeel I was-wastin myself The two quotations show how Sally Carrol tries to tell her friends that she needs to move on. After meeting Harry again she visits the North with him to spend some time. The contrast from the South shocks her especially the weather and she feels that the weather reflects the people there, cold. Sally Carrols first vision of the North is when she is on the train there. The train becomes very cold and Sally Carrol wants another blanket. The pace of the writing becomes rather intense, as the Pullman gets closer to its destination. two tracks ran up beside the train-three-four As the train enters the urbanised area, it speeds up the pace until eventually it stops at the frosty station. Sally realises almost immediately that she will not like the North as it is such a contrast to the warmth of the South and there are many unfamiliar faces. Sally finds the people cold and the people seem to be hidden away underneath coats. saw three fur-bundled figures In The Ice Palace there are two main significant places. These happen to be the graveyard of which Sally Carrol loves and has a place in her heart. One gravestone is especially meaningful to Sally Carrol and this is of Margery Lee. Margery Lee is the symbol of the South, a kind of motherly figure like the Southern Belle. The other significant place is the Ice Palace. When Sally Carrol goes to the North to stay with Harry they visit the Ice Palace. Harry is very excited about this and looks forward to it. In the Ice Palace, Sally Carrol loses Harry and all the lights go out. Sally Carrol panics and begins to think of the cold, ghosts and death. The cold and quietness of the Ice Palace symbolises Sally Carrols dying love for Harry and she realises that her relationship will not work with him when Margery Lee talks to her in her head. your tears would just freezeall tears freeze up here! Sally Carrol is rescued by Harry but has already made up her mind to return to the South as she realises her friends are much more important. The language style that F.Scott Fitzgerald uses to continue the South is the same description as in the introduction. It goes back to describing Sally Carrol eating an apple. Sally Carrol seems to have an easy life. She made the decision to move to the North and live with Harry but found that the North did not have the atmosphere to her liking so returned. The two stories are very closely related in both decision-making and also the way in which both women see men as a way to get to be a person society. They have very different decisions to make and for Phyllis her decision could change her whole life and there would be no way out. Sally Carrol experienced her choice and then decided that it would be better to return to her old life and carry on as normal without being thought of a different. It is clear to see that both women needed to marry to have a good life and in Phyllis case she needed to marry young to be respected when older. In Sally Carrols case she returned to her normal life knowing that if she wanted she could get married whenever she wanted as she was in different circumstances and was prettier. A third short story, which I read, was called Desirees Baby and also involves womens choices. Desiree was adopted when a child and managed to make a good marriage with a plantation owner. She had a baby who appeared to be of the slave race and she was rejected by her husband. In the face of her pain and humiliation Desiree decided to choose death for herself and her baby. After Desiree had left, the husband finds a note from his mother to his father. He learns that his mother was of the slave race and he had wronged his wife by dismissing her and her child. All three women had very major and hard decisions to make. They all had to choose what to do, as they could not just live their lives as normal. All three women were in different circumstances and under different social affluences. Sally Carrol is the main woman who could choose to go and then return to her normal life if she disliked it and she took that opportunity. The other two women either had to go or stay. Desiree decided to go and took her life, Phyllis decided to stay and suffer which meant that she did not have a happy life anyway. Life through the years has had a major effect on womens choices and the way they make decisions. If a woman is faced with a major decision today she has the right to do what to do without male interference. Men were respected and if a woman wasnt married, she was not treated the same in society. In the present day, women can have careers without being criticised and live a normal happy life without the need to get married and they are not treated much differently at all. Influences and affluences play a major part in life but in the twenty-first century women can make their own choices and are becoming as dominant as men.

Project management Essay Example | Topics and Well Written Essays - 2500 words - 1

Project management - Essay Example As recommended by literature (Field and Keller 2007, p.198), the forward pass mode has been used for calculating the ETS for each of the activities. The mode is based on the assumption that all previous activities have been finalised. The following equation has been used in calculating its values: ETSj  = max (ETSi  + Ti  Ã¢â‚¬â€œ i - when an activity is linked to j on an arc from i to j). The values of ETS for each of the activities are provided in a Table 1. Early Finish Time (EFT) is calculated by adding the duration time of each activity to its ETS. The Late Start Time (LTS) is calculated through the use of backward pass mode. It is based on the assumption that the latest time the last event can occur is equal to the last event ETS. The following equation has been used in calculating its values: LTSi  = MIN (LTSj  - Ti  -j is an activity linked to i on the path from i to j). The values of LTS for each of the activities are provided in a Table 1. Float The total float in the scheduling provides information on the accepted event delay that will not result in total delay of the whole project (Field and Keller 2007, PMI 2008). It is the difference between the LTS and ETS of each project activity, i.e. Fi = LTSi–ETSi 3. The project duration and the critical path. The minimum required time for the completion of the project is 80 days. A final step in designing the network is the identification of the critical path. A critical path is made out of the critical activities of the project. An activity is assessed as critical when if delayed, will cause a delay of the whole project duration by an equal amount of time (Field and Keller 2007:183, PMI 2008). For a critical activity: The ETS and the LTS of the activity must be equal at the each node; The Float must be equal to 0; Table 1. Task Name Duration Pred. Early Start Early Finish Late Start Late Finish Float Critical path A 4 - 0 4 0 4 0 yes B 4 A 4 8 4 8 0 yes C 2 A 4 6 14 16 10 no D 6 A 4 10 10 16 6 no E 5 A 4 9 11 16 7 no F 8 B 8 16 8 16 0 yes G 10 C,D,E,F 16 26 16 26 0 yes H 7 G 26 33 26 33 0 yes I 6 H 33 39 33 39 0 yes J 5 H 33 38 34 39 1 no K 7 I,J 39 46 39 46 0 yes L 14 K 46 60 46 60 0 yes M 8 L 60 68 60 68 0 yes N 2 M 68 70 68 70 0 yes O 2 N 70 72 76 78 6 no P 8 N 70 78 70 78 0 yes Q 2 O,P 78 80 78 80 0 yes 1. Different Project Scenarios If the project starts on Monday 21st, May, 2011, what is the earliest date it can be completed using a 5 day working week? For calculating the schedule and the earliest date the project can be completed, the project management tool - Gant chart is used, presented in Appendix 2. The calculation is as follows: the total duration project of the (80) is divided with 5 (working days in the week) = 16 weeks. The earliest date is for completion of the project is Friday, September 2nd, 2011. If the following happened what would be the effect on the duration of the whole project? Explain the reasons. a. A two day delay in activity

Government Intervention in Market Operations Essay

Government Intervention in Market Operations - Essay Example In addition, the firm may create differences in employee skills like the education level or training received. Products may be differentiated through the distribution of the products. This could occur through internet shopping like the Amazon.com that is a modern online store and differentiates itself from the traditional stores. This type of market structure is realistic since there is product differentiation. Firms make independent decisions in regards to prices and production costs (Bordo & Humpage, 2006). In addition, since there are no major barriers to market entry or exit, people are free to enter or leave the market. Moreover, firms make independent decisions in regards to price and the output as well as the production costs. The U.S government has implemented the fiscal policy that helps control the level of demand for different products as well as the economic demand pattern. It generally describes the impacts on the aggregate economy and the overall spending and taxation. Taxes are the major source of revenue by the government. The government also provides subsidies and contracts to public works as well as the salaries of the employees. The taxation and spending are sources for driving demand and increase the growth of the economy. Fiscal policy entails the government making a decision about the goods and services it buys, the collection of taxes and distribution of transfer payments. The main goal of the fiscal policy is to observe and maintain a high economic growth as well as ensure there is full employment (Fatum & Hutchison, 2003). Moreover, it helps the U.S government make decisions on whether it will spend more or less than it gains. There are two types of Fiscal policy, the expansionary, and th e contractionary policy. The main objective of the expansionary policy is to create growth and stimulate the economy. In addition, the government either reduces taxes or spends more.  Ã‚  

Web-enabled Database Essay Example for Free

Web-enabled Database Essay To keep certain information in a corporation, many different set ups are planned and followed so that the data may remain intact and secure as these data information of various departments are pretty essential to keep the flow of work steady and at a proper pace. So, once this information is stored the next step is to make sure that it is safe and can be retrieved whenever required without creating any problems. So, to deal with such circumstances where data retrieval can be required at anytime a production business or a firm must comprise of an appropriate database management system. Database management systems are necessary because today every thing is computer based and all the data and information is stored, circulated and modified through its use, therefore database management system are quite necessary in running an organization without hindrances. Database management systems are either software based which require a certain certified software program which can be installed in the PC to make it work in the company while the other kind is the internet or the web-based or web-enabled database management system. It is a suitable process that is applied many conglomerate corporations and big businesses producing efficient and rapid results. The background of internet-based instruction is altering due to the union of the internet and database servers. This paper looks at and describes some of the characteristics, purpose, and interoperable features of Web-enabled databases as they are improving the internet-based instruction by providing advantages to many users (Scamell Umanath, 2007). Database and Web-Enabled Database: A database contains properly planned collection of data for various functions and is mostly in digital figure. A method of making categories in database is through their matter like bibliography, records and calculation purpose. Digital databases work is carried through the use of Database Management Systems which is software that is installed in the PC to help in storing data, allowing data forming, and maintenance. Database programs are software applications anticipated for customers to make databases and produce all the programming required to fill them or get rid of them as wished. The display of a database is like a table of a spreadsheet, which consists of rows and columns of records. The columns categorize the characteristics in the table, and the rows are the documentations of the respective data. These tables one way or another look precisely like a spread sheet though the database tables can be influenced and updated in a manner that usually spreadsheets can not perform, and because of this characteristic it crafts a database into a exceedingly significant device (Scamell Umanath, 2007). While, since the internet has become a major part of our lives so it is being used in almost every work due to speed, reliability and easy access with out any problems so database management systems also got modernized in shape of web-enabled database. Web-enabled or web-based database smooth the progress of virtual society to converse, find sources for database queries, convey immediate reaction, and modify instructional progressions however it can also be described as a system that makes the availability of central administration of resources, online records compilation, online arithmetical examination, and mutual investigation. The web enabled database varies from a local database as it is installed in a personal computer or its connected storage, for instance a CD. Therefore it benefits the corporation in managing their data in a proper and efficient way so that no mishap can occur once the data is required urgently. Layers of Database planning: Any database system, be it web-enabled or non-web enabled, requires proper arrangements for operation and these arrangement which are an integral part of the system are usually known as layers. There are three layers of database management system or planning known as external, conceptual and internal. The primary feature of the Relational Database Model passed in 1969 by Edgar Frank Codd as First-Order Predicted Logic invented these three layers for the data base management system and this feature stills controls the 21st century databases systems which are enhanced due to the feature of internet in them. The reasons for designing these layers are appropriate working of the database system and in a proper sequence because sequencing in data storage is essentially required plus it does not create any mix ups that might lead to data lost in future. The external layer explains the process and procedure that how the customers or users should understand the relationship of the data. Any particular data file or document might contain a certain amount of readings, records or observation at external layer. When it comes to the design of the internal level or layer the purpose of internal layer is to provide a clear picture of the actual storage of data and its development by the computer system. Basically the planning of internal layer concerned with expenses, arrangement, scalability and other certain essential objects of data packets installed or used by the clients (Scamell Umanath, 2007). While the layer that amalgamates or connects the previous layers i. e. internal and external is the conceptual layer. It supplies a general examination of the database by providing a clear view of the company’s data is storage or supervision, and it can merge the various external views into a reliable data. In these all three layers active directory makes available of a hierarchical data reorganization space. Every data object is exclusively recognized in the database by its entity identification quality, called the Relative Distinguished Name (RDN). The relative distinguished name when joined with other major components frames the objects Distinguished Name (DN). The database stores the RDN of every data object plus an indication to the main source object so that database layer can tag on these parent indications and concatenates the following RDN to construct DN. A chief purpose of the database layer is to interpret each DN into a numeric arrangement called the DN tag, which is used for all internal accesses. Reasons for introduction of web enabled database: When the internet became an essentially used component in the computers it was believed that more people would head towards internet based software due to easy access and reliability. So the database software were also introduced for web-based working so that people can use them instead of the installed software, it was due to the fact that if internet is constantly being used in the company everyday so using the web-enabled database would be cheap and reliable as no space in hard disk would be used but the one that is virtually allocated to the user (Scamell Umanath, 2007). Also, for small or local companies it is difficult to install and to afford the price of the database management software as they are quite expensive due to certified and authorized. An example of it can be given through this illustration that a corporation might already bring into play a constant link for email and web-browsing, and be in a site to take advantage of it further for a web-enabled database because if it opts for the selection of database software than almost a figure of ? 10,000 per annum, as per financial plan, would be required for to install and program it which would also be used to check emails and internet usage if desired however the precise figure will depend a lot on the quantity of transfer and usage of the database the company wishes the site to produce. So, this is quite an expensive amount for small scale industries and businesses which do not produce a lot of revenue, therefore keeping in mind the situations these companies might face the web-based or web-enabled database were initiated. Also apart from small industries these databases are also used in schools for keeping the proper record of the student body admitted in school since it got established therefore schools cannot afford such expensive software which are basically constructed for the large scale businesses and corporations. Thus in these circumstances people take the options of selecting the web-based database due to easy access and result, these database are also sometimes referred to the search engines which are used all over the internet and provide easy and fast results so same is with the output of the web-enabled database (Scamell Umanath, 2007). Differences between web-enabled database and non web-enable database: When it comes to the distinguishing of both categories of databases the basic and the primary difference is the internet usage. In web-enabled databases the internet is the base on which the whole database is established while the ones which are non web-enabled are software based however they do provide the access to the internet for various reasons. But there is a great deal of difference between software which is installed in the hard disk for usage and the one which is available on the World Wide Web for benefiting results and availability. So, when it comes to the point of availability, the non-web based databases have higher availability as they are installed in the computer and can be run any time however in case web-enabled database the availability same as non web-enabled database if the connection of internet is available through out and no problems occur during the connectivity because for the web-based database internet connection is essential and a fast one, to be clear. So availability of both the databases are some how the same depending upon the situation the user is in as some might go against web-enabled databases due to poor network connectivity. As far as backup is concerned, web-enabled databases are recommended due to the reason that any system failure or hard disk crash can lead to a loss in non web-enabled databases unless there is a storage device apart from the hard disk space, while web-enabled database have a virtual space or backup due to which the data is safe so priority goes to the web enabled database over the non web-enabled database in case of backups. However the recent development in the database software is this that now back up plan is also available in the software CDs so this might overcome this weakness (Scamell Umanath, 2007). Performance and compatibility of recent software based database has improved a lot due to development in research of making the software applications reliable and efficient however the more fast they are the more space they require in the hard disk, so it eventually affects the computer’s speed of work unless the system is sort of a super computer. In this case the web-based database are recommended, noted that the network speed should be fast enough to run the program, as the space is allocated virtually and no need of over sized data is required in the PC. Internet connection can have a major affect on the performance of web-enabled database as any uploading might slow down or even get cancelled due to poor speed so once a user is following the web-based databases then he or she should make certain if the network speed is supportive. The selection of development team is more reliable in software based database installed in the computer because any changes in the software can be made however this feature is not very common in the internet based database as the only purpose is to provide the database technology via internet usage and the user cannot make any changes in the software which is on the internet while any changes can be made in the one which is installed in the PC so for the selection of team for its development the better is the installed software as the development team can make the changes which the require and this cannot be done in web-enabled database. Security on internet is a confusing term because most of the people go against the fact that internet is secure in safe guarding the data while the database providers go against it as they believe that firewall has a lot of effects but due to the presence of hackers in all places the internet based databases are not recommended for big corporations as it is better safe than sorry for them, therefore if compared then installed software is more reliable in security as the user can have all the authorities in placing the privacy and security(Scamell Umanath, 2007) . Therefore web-enabled database are somehow better but not always a person can rely on them as security reasons are very essential for data storage. Conclusion: The amalgamation of the database servers develop Web-based instruction by offering advantages to the small scale industries and other users who cannot afford expensive database software applications for storing and sequencing the data as per the requirement and necessity. References: Scamell, R. W. Umanath, N. S. , (2007), Data Modeling and Database Design, 1st edn, Course Technology, USA

The Year of the Woman Essay -- mh

The Year of the Woman Reporters portray female and male candidates differently when covering campaigns for political office. In order to counteract the biased coverage in the papers the women of the 1992 Senate race used 30-second advertising spots to assert their key issue stances and strengths. Though this was not the sole purpose of their ads, they were very much geared toward compensating for the lack of fair coverage they were receiving in the news. Ultimately they persevered. Through verbal and nonverbal content, as defined by Lynda Lee Kaid, women designed their ads to portray a high level of competence. 1992 is widely known as 'The Year of the Woman,' when 5 women won Senate seats and 24 new women were elected to the House. "All male Senate races received more press coverage than races which included female candidates,' but despite male biased journalistic media coverage, 'women of the 1992 election succeeded with strong campaign spots," that helped them redefine themselves to the public and win c onstituent votes. Though women and men receive an equal amount of coverage by newspapers, "the content of the coverage that women receive as opposed to men, during an election is extremely different and male biased." Newspaper readers are more likely to read about a female candidate's personal life, appearance, or personality while reading about a male's stance on governmental issues. This gives the man more credibility as a candidate. Compared to coverage of male candidates, coverage of a female candidate is, "more personal, less issue based, and less likely to include evidence or reasoning to support quoted remarks". Ultimately women are portrayed as less informed on issues and instead as icons rather than educated citize... ...er women in this study won representation of their state. Each woman focused her ad on something different. It is clear that Braun's ad is heavily laden with endorsements, legislative achievements and highlights of power and leadership while at the same time concentrating a huge portion of the ad on family values. Boxer's theme was to fight for change and Dianne Fienstein highlighted her achievements in the face of undue hardship. Seargant and Ferraro took their ads and focused on highlighting power and leadership. Ultimately all of the women had feminine ad campaigns that were positive outlooks on women rather than weak, negative and superficially concerned. Though men started out with an unfair advantage of positive journalistic media coverage in 1992, women created ad campaigns that overcame the unbalance and won more seats in the House and Senate than ever before.

Internet Privacy

Joyce Betts 03/04/2013 Week 4 Assignment Short Critical Reflection Paper The three Questions I have chosen are: * Online education has evolved over the last ten years as much as the cell phone. Given this, what have been some of the major improvements and changes in the digital classroom? In the 1900s, few universities had online classes. Today, online education is one of the most exciting and revolutionary aspects of our education. Ashford University is one of the top ten online schools, and by now you have a good understanding of how it works.Course management systems are software programs that define the online classroom environment. In late 2009, Ashford University made a change from Blackboard to eCollege software. Most educators believe that Blackboard is one of the most basic systems in distance learning. On the other hand, some people have called eCollege a â€Å"force to be reckoned with† (Babb & Mirabella, 2007,p. 162). With a growing demand for these systems among e ducational institutions, the developers will continue to put pressure on each other to improve their products.This benefits the student, because it ensures that course management software will continue to evolve and enhance the online learning experience. * What types of strategies can educators use to ensure their students are not â€Å"flaming† in a way that causes damage to others? Flaming is a term that describes an increasingly intense and vicious debate. Always avoid offensive language, and be sure to reread everything you write so that it cannot be interpreted as offensive in any way.Never share personal material about any other classmate in a post. Opinions are important to share, but do not make posts a stage from which to broadcast your personal views of life. Making sure each and every student understands the rules of proper etiquette. Finally, if you have a question about something you what to write or about what another student wrote, email your professor private ly. If I post a poem on my Facebook site and someone cuts and pastes it on their site is that a case for stealing my intellectual property?I do not think this is stealing my intellectual property. If you did not want it posted on other sites you need to copyright it. In conclusion, the dark side of the internet will always be with us. If you arm yourself with knowledge, install advances software protection, and license your intellectual property, you should have save experience. References: Bowles, M. D (2010). Introduction to computer literacy. San Diego, CA: Bridgepoint Education, Inc. Chapter 8