Hydrochloric acid and magnesium Essay Example for Free

Hydrochloric acid and magnesium Essay The temperature raised considerably on the other 4 due to the quickness of the reaction. This heat would quicken the reaction due to the fact that the molecules would be vibrating and therefore colliding more often (as explained before).   Sometimes the magnesium floated on the top of the acid. This was not a problem in most cases because the bubbles over lapped the magnesium so it also reacted from the top. However, due to the 0. 5 mole slow reaction, this did not happen. Because of all these inconsistencies, it is difficult to say how reliable my results are. I think that because the results are what I expected, and because I carried out the experiment with care, also the fact that I repeated the experiment many times makes it highly unlikely that the results are inaccurate enough to not be able to draw a valid conclusion from. Evaluation This was a good experiment because it clearly showed my prediction, and where it didnt I was able to spot the errors and am now able to make the experiment better. I worked as I kept a fairly high degree of accuracy, and the experiment had a high margin of error, due to the length of time some of the results could to take. My results were fairly accurate but my error in the rate of reaction of the 0. 5 mole acid could have been down to accuracy, but I seriously doubt it, as I asked around to see if other people had encountered the same problem. Everybody had. I have several theories of why the 0. 5 mole acid did not react as expected.   The temperature raised considerably on the other 4 due to the quickness of the reaction. This heat would quicken the reaction due to the fact that the molecules would be vibrating and therefore colliding more often.   Sometimes the magnesium floated on the top of the acid. This was not a problem in most cases because the bubbles over lapped the magnesium so it also reacted from the top. However, due to the 0. 5 mole slow reaction, this did not happen. To make my experiment more accurate I could have Weighing the magnesium instead of just measuring the length of it. This was an obvious problem as I think my spread of results for the end amount of hydrogen given off was too high. I would have preferred if it were only 1 or 2 ml. But it was 4. 33ml   Setting up another system for getting the magnesium into the acid. When I did the experiment I just dropped the acid in and attached the gas syringe as quickly as possible. The disadvantages with this were:   It was inaccurate   The start of the reaction would be when most gas was given off. The time of attaching the gas syringe was always different.   The gas syringe often jumped forward slightly when I put it on.   Repeated the experiment more times.   Used more acid. This would shop the temperature problem as the temperature would be less likely to change, due to the increase in energy it would take to heat the water. Because of all these inconsistencies, including the 0.5 mole acid result, it is difficult to say how reliable my results are. They are not accurate enough to study the experiment in-depth, however for a general hypothesis such as Aiming to find out whether the concentration of acid effects the speed at which gas is given off, between hydrochloric acid magnesium ribbon and because the results are what I expected, and I carried out the experiment with care, also the fact that I repeated the experiment many times, it is reasonable to presume that I can draw a simple conclusion like, the higher the concentration, the quicker the gas will be given off. If I were to do the experiment again I would change the way I inserted the magnesium into the flask. I think I would have a double chambered flask that would be able to have the wall removed. See diagram. I could combine this idea with the alternative way I could do the experiment, as described in my planning. The method would be to: Place magnesium and the acid in a flask, which is then plugged with cotton wool, to prevent any liquid splashing out, during the reaction. Next, the flask is weighed, then tipped up to let the reactants mix and a clock is started. The mass is noted at regular intervals, until the reaction is complete. I would use the same volumes for all the chemicals in the new experiment, as I see no good reason changing them. I would expect the graph for the result to be much the same, but obviously with different axis labels and values. For example In conclusion, the experiment did prove my prediction that the rate of reaction doubles with when the acid strength doubles. Daniel Hill 10S Rate of Reaction Between. doc Page 1 of 8 Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour section.

Why Did The Polls Get It Wrong In 1992? :: essays research papers fc

Why Did the Polls Get it Wrong in 1992? Opinion polls play a major role in politics, they can be used by the Government to decide when to call and election, and, among other things, how their pre- election campaigns are run. Throughout the history of opinion polling, from the time when polling began to be widely used before an election, in 1945, until 1987, the last general election before 1992, the polls have on average been correct to within 1.3% of the vote share between the three leading parties, and the 'other' category (Crewe, 1992, p. 478). This puts all the previous opinion polls well within the +/-3% margin of error. Because of the past accuracy of opinion polling, the system has had great credibility and has always been trusted, both by the public, and political parties. The way polling forecasts can affect the way people vote is very dramatic, this is because they can be a 'self fulfilling prophecy', in that some voters like to back the 'winning team', and others only vote for a party they feel has a real chance. This was demonstrated in 1983, when the Alliance, frustrated with the media concentrating only on their position in the polls, leaked their own private polls to the press, resulting in a late surge of support (Crewe, 1992, p.478). Britain generally has a much greater number of opinion polls carried out than in other countries, this is due to the large number of national newspapers, and the amount of current affairs programming on television. The period prior to the 1992 general election saw a much greater intensity of opinion polling than ever before. During the 29 days between the date of the announcement of the actual election date, 11th March, and the election date itself, 9th April, there were a total of no less than 57 national opinion polls. The 1992 election will always be remembered as the one the pollsters got wrong, during the lead up to the election, they almost all showed Labour ahead of the Tories. Of the four polls carried out in the two days prior to the actual election date, all of them pointed to a hung parliament; one put the Conservatives 0.5% ahead, one put Labour and the Tories neck and neck, the other two showed Labour ahead by a narrow margin (Crewe, 1992, p. 8). On the actual day of the election, exit polls carried out by the BBC and ITN both showed there would be a hung parliament, although both of them had the Conservatives slightly ahead. They were both not far from the actual Conservative 43%, and Labour 35%, Why Did The Polls Get It Wrong In 1992? :: essays research papers fc Why Did the Polls Get it Wrong in 1992? Opinion polls play a major role in politics, they can be used by the Government to decide when to call and election, and, among other things, how their pre- election campaigns are run. Throughout the history of opinion polling, from the time when polling began to be widely used before an election, in 1945, until 1987, the last general election before 1992, the polls have on average been correct to within 1.3% of the vote share between the three leading parties, and the 'other' category (Crewe, 1992, p. 478). This puts all the previous opinion polls well within the +/-3% margin of error. Because of the past accuracy of opinion polling, the system has had great credibility and has always been trusted, both by the public, and political parties. The way polling forecasts can affect the way people vote is very dramatic, this is because they can be a 'self fulfilling prophecy', in that some voters like to back the 'winning team', and others only vote for a party they feel has a real chance. This was demonstrated in 1983, when the Alliance, frustrated with the media concentrating only on their position in the polls, leaked their own private polls to the press, resulting in a late surge of support (Crewe, 1992, p.478). Britain generally has a much greater number of opinion polls carried out than in other countries, this is due to the large number of national newspapers, and the amount of current affairs programming on television. The period prior to the 1992 general election saw a much greater intensity of opinion polling than ever before. During the 29 days between the date of the announcement of the actual election date, 11th March, and the election date itself, 9th April, there were a total of no less than 57 national opinion polls. The 1992 election will always be remembered as the one the pollsters got wrong, during the lead up to the election, they almost all showed Labour ahead of the Tories. Of the four polls carried out in the two days prior to the actual election date, all of them pointed to a hung parliament; one put the Conservatives 0.5% ahead, one put Labour and the Tories neck and neck, the other two showed Labour ahead by a narrow margin (Crewe, 1992, p. 8). On the actual day of the election, exit polls carried out by the BBC and ITN both showed there would be a hung parliament, although both of them had the Conservatives slightly ahead. They were both not far from the actual Conservative 43%, and Labour 35%,

Background of the Study Essay

In the recent years, mobile phone usage has been in its rapid growth. 80% of the world’s population now has a mobile phone. Based on the statistics, there are 5 billion mobile phones in the world out of which only 1. 08 billion are smartphones. According to the research compiled by GfK Asia, smartphones have taken over the market for mobile handsets in Southeast Asia. Also GfK Asia says that in countries like Singapore, Malaysia, Thailand, Vietnam, Indonesia, Philippines and Cambodia, growth in smartphone use year over year ranged from 40% to as high as 400%. The smartphones market in the Philippines grew the fastest among Southeast Asian countries over the past year, which also recorded the fastest increase in market share versus feature phones. Most of the mobile phones nowadays are addressed as â€Å"Smartphone†; because they just not only provide original telephone features, but also various functions that can be done with other devices, such as PDAs or computers. Along with the smartphone fundamental capabilities to make voice call, video call, SMS, and MMS, smartphone have been repositioned as a ? new information medium (May & Hearn, 2005). These new functions make smartphones different from regular feature phones. Therefore, the society has slowly moved their cell phone purchasing decision to smartphone (Min, et al. , 2012). Smartphone technology is inevitably changing peoples’ behaviors; especially young adults using smartphone frequently today. CourseSmart, which is the world‘s largest provider of digital course materials and eTextbooks, found that university students can‘t go long without checking their digital devices, including smartphone, laptop and more (CourseSmart, 2011) University students are very in to checking their accounts in Facebook, Twitter, Instagram, or even sending emails etc. using smartphone with their web connection feature. Today, students are using their smartphones for nearly everything and they consume mobile information almost everywhere that allows them. Therefore, consumers are highly concern with technologies that they might change their devices from time to time. In other words, due to the advancement of technology devices can be easily replaced. Hence, for the smartphone manufacturers it is essential to know what factors that actually affecting purchase intention of smartphone among young adults.

Essay on Cloning Informative Speech - 1597 Words

Cloning and Stem Cell Research S/P: To inform my audience about cloning and cell stem research. C/I: The benefits and ethical issues of cloning and cell stem research. Introduction Specific purpose: Today I’m going to inform you about â€Å"Cloning Technology and Stem Cell Research†. Attention getter: Imagine yourself dying from heart disease or liver failure, and the only way to live was to have an exact clone of your heart or liver. The only way this could be possible was to have an exact copy made by your organs, and this process is achieved only by cloning. Reveal central idea: Stem cell research and cloning, is one of the most exciting and controversial ethical†¦show more content†¦Diabetes: People who suffer from type I diabetes have problems with the regulation of insulin. In this case research says that by taking some of this cells who are not capable to produce insulin, in laboratory conditions we can guide this cells to generate other cells that will be able to produce insulin. Then transplant these cells into diabetics, in order to remove their need for insulin injection. B. Transplanting damaged organs. Stem cells are very important in this process, because from your own cells scientists can develop organs. And if you will need any transplant this organs can be used at any time and have no risk that your organism might reject them. The first successful transplant from this technique of â€Å"growing your own organs† took place in Barcelona, Spain 2008, and this was a 30-year old woman from Colombia, who replac ed her windpipe because of tuberculosis. C. Testing medications and drugs. Stem cells have an important role in this field. New drugs and medications can be tested on stem cells to see if they are safe, before we use them on humans or animals. Scientists by doing this tests can find new ways to treat some diseases. For example a cancer cell can be created to test an anti-tumor drug. If the results will be positive we will have a cure for that kind of tumor. (Transition: The final part that we will look at is the ethical issues and government funding of stem cellShow MoreRelatedPeer Pressure2910 Words   |  12 Pagesbe a welcome break from citing Mark Anthony s oft quoted, Friends, Romans, Countrymen... speech. A good debate topic does not necessarily need to be a political topic. It can be funny, informative, contemplative, social, economical - the categories are endless. Debate topics for students need to be chosen keeping in mind the maturity level and understanding that they may be expected to have about the speech topic at hand. Always make a shortlist of topics that will seem interesting to the targetRead MoreSources of Ethics20199 Words   |  81 Pagesand needed an ethical decision; he begged God for guidance: Till, when they reached the Valley of the Ants, an ant exclaimed: O ants! Enter your dwellings lest Solomon and his armies crush you, unperceiving. And [Solomon] smiled, laughing at her speech, and said: My Lord, arouse me to be thankful for Thy favor wherewith Thou hast favored me and my parents, and to do good that shall be pleasing unto Thee, and include me among [the number of] Thy righteous slaves (Surah 27:18-19). Ethics in IslamRead MoreOrganisational Theory230255 Words   |  922 Pagesorganization theory: back to the future? Case study (Continued ) Climate survey results As soon as a full analysis of both qualitative comments and quantitative information has been completed by staff, these are presented in a very simple yet informative format. This might include: †¢ †¢ †¢ †¢ †¢ †¢ †¢ a summary and overview of the survey response a comparison against past survey data benchmarking against other organizations outcomes and trends of each factor which the questionnaire was designed to measure