The rate of reaction Essay Example for Free

The rate of reaction Essay Add 50 cubic centimetres of hydrogen peroxide to a conical flask Add liquidised celery solution to hydrogen peroxide and place bung over conical flask After 30 seconds, see how much oxygen has been produced Celery Concentrations Volume of Celery (cm3) Volume of water (cm3) Concentration of celery (%) 80 20 80 60 40 60 40 60 40 20 80 20 Results Tables First Repeat Time (seconds) Celery Concentration (%) Amount of hydrogen peroxide (cm3). Volume of oxygen produced (cm3) Second Repeat Time (seconds) Celery Concentration (%) Amount of hydrogen peroxide (cm3) Volume of oxygen produced (cm3) Third Repeat Time (seconds) Celery Concentration (%) Amount of hydrogen peroxide (cm3) Volume of oxygen produced (cm3)Â   Averages Time (seconds) Celery concentration (%) Amount of hydrogen peroxide (cm3) Volume of oxygen produced Analysing evidence and concluding From the graph I have drawn using the above table of averages, I can see that as the concentration of the enzyme catalase increases, the amount of oxygen produced also increases. I can also see from my table of results that as the concentration of the enzyme increases, the volume of oxygen increases. This shows that the rate of reaction increases, which supports my prediction. The reason for this is the Collision Theory, as stated in my prediction. The Collision Theory states that the more particles there are in a solution or area, the higher the rate of reaction will be because there are more particles, therefore there are more collisions, meaning there is an increased chance of successful collisions in which the two particles react. In this experiment, when the particles react, they break down the hydrogen peroxide and create oxygen and water. As the volume of oxygen increased with positive correlation to the amount of the enzyme in the mixture, I can see that the rate of reaction was increased, thus proving my prediction to be correct. Please see also attached graph. Evaluation The experiment was relatively easy, in that the variables were easy to identify, control or measure, which means that the readings from the experiment should be very accurate. The apparatus was set up in such a way that I think the results are very reliable. The tubing and bung all fitted well into their respective receptacles, thus no oxygen could have escaped from there. The only time and place the oxygen could have escaped was the period between adding the liquidised celery to the hydrogen peroxide, and placing the bung into the conical flask containing the mixture. Unfortunately, there was nothing I could do to stop this, except try and replace the bung as quickly as I could. There do not seem to be any anomalous results, except in the third repeat when I was using a concentration of forty percent celery. After ten seconds, I measured no oxygen whatsoever, and I presume this was due to a fault in the tubing; perhaps there were slight gaps that I had overlooked during that repeat. However, as this is the only time there is an anomaly within the results, I must assume that the rest of my results are accurate and reliable, and therefore the equipment was set up correctly and performed well. I think that my results are sufficiently reliable to support my conclusion (see above) because they match my prediction and scientific knowledge of this subject, and the figures I have obtained seem reasonable. I know they are accurate because I was careful to be accurate when taking readings from the gas syringe, and I am sure they are reliable because they do match scientific theory, as taken from text books, etc. , and my prediction, which was made using scientific knowledge from various sources. To improve the reliability of the experiment, I think it would be necessary to find a way of feeding the celery into the conical flask, perhaps via another tube system, where it would be possible to add the celery to the hydrogen peroxide without losing any of the oxygen produced.

Self-Concepts in Julius Caesar :: Julius Caesar Essays

Self-Concepts in Julius Caesar All people have definite concepts of self. In different situations, one may feel short, tall, smart, slow, fast, talkative, reserved, etceteras. These self-concepts are usually very different than how others view us. Depending on one's actions, words or even tone of voice, one may misrepresent oneself and be misinterpreted. One may be so arrogant or so humble that they prevent themselves from seeing themselves through others' eyes. In William Shakespeare's play Julius Caesar, two main characters, Julius Caesar and Marcus Brutus, present different personas- one being each characters actual self-characterizations, which we learn through their discussions with others, and another is how they are actually perceived in the eyes of others. Their inability to project their true motives in performing certain actions eventually brings about their tragic downfalls. Julius Caesar believed that people needed one strong ruler in order to have maximum production and proper function of a society. He believed that he possessed many, if not all, of the characteristics required of a great leader. He spoke to others in a way which he believed exhibited authority, told people why he should be the one to lead them, and thought that his own advice was best. His unwillingness to listen to others is received as arrogance. Though already warned by the soothsayer to "beware the ides of March," Caesar refuses to heed advice to stay home from Calpurnia, his wife, because he feels that she is trying to keep him from obtaining power and status. Calpurnia believes Caesar to be a prince and is convinced that some falling meteors are warnings of a prince's death. When she hears her husband boast that he is more dangerous than danger itself, she recognizes that this is simple arrogance, and tells him so, saying, "Alas, my lord/ Your wisdom is consumed in confidence (Act II, scene 2)." In response to her criticism and humble petitions, Caesar momentarily agrees to pacify her. However, when he changes his mind and decides to leave against her admonitions, she reluctantly, but obediently fetches Caesar's robe and he departs for the Senate, and his meeting with fate. Caesar's greatest character flaw, however, is thinking that he is far above others and somehow invincible. When he compares his own perseverance with that of the North Star, saying "But I am as constant as

Describe the employment of women in Britain in 1914 at the outbreak of war

As war broke out in 1914 about 1/3 of women were in some type of paid employment. The majority of this was domestic service or secretarial work and most people accepted, there was no place for women in manual labour e. g. dock-labouring, mining or road -digging. A woman's role was very much as the homemaker. They were regarded as the weaker sex and the sex that had fewer rights than men. Decent women were expected to stay at home and rear the children of the family. They had to obey their husbands. Britain's leisure class was kept in comfort by an army of domestic servants. A large landowner with a wife, two children and a 62-roomed house n the West End required an indoor staff of 36. Some of the servants accompanied the family to its other homes – the country house, the seaside villa, the ‘shooting box' in Scotland – each of which also had its own separate staff, containing many women. The working day could be a gruelling 17 hours long. The most important female servant of the household was the housekeeper, known by the title of ‘Mrs', she commanded a platoon of female domestics like lady's maid, housemaids, kitchen maids and the scullion who washed the dishes. Upper class women were not expected to work. They therefore were involved in charity work and voluntary work also they were heavily involved with the suffragettes. Many working class women worked all day at jobs in their own homes, however some working class women worked in factories, to supplement the men's income, which often wasn't enough. Workrooms were often crowded, dirty, ill lit, ill ventilated and insufficiently heated. The hours permissible under the Factory Acts in 1901 were long. Women and girls over 14 years could be employed 12 hours a day and on Saturday 8 hours. In addition, in certain industries, and dressmaking was one, an additional 2 hours could be worked by women on 30 nights in any 12 months. At the outbreak of war women earned about 65 per cent of the male wage. The employment of little errand girls, usually only 14 years of age was common. Their work was very varied – running errands, matching materials, and taking out parcels, cleaning the workrooms, and often also helping in the work of the house. To be running around doing ‘odd jobs' for the employees of a busy workshop was hard work and tiring. It was not surprising that the young women in those workshops often looked weary and overdone; but there were plenty of girls to take their place, so they would not give in. Many others were employed to work on the surface of coal mines or on fish docks at hard, tiring, physical labour. A sexist outlook upon women in the workplace operated throughout this period. It resulted in skill definitions and pay differentials. Women's work was usually considered unskilled, where as a man doing the same job would be considered skilled. For example welding was perceived as a skilled job when men did it but when women became welders during the First World War it was seen as unskilled, with women being paid half the male rate. Middle class women attempted to get into professions as doctors, lawyers, accountants and bankers but found it incredibly difficult. The opinion of men was that they were not intelligent enough and too weak emotionally therefore unable to cope with the work. They did find employment easier to find as teachers, as this was dealing with children and they were able to find employment in the white-collar industries as clerks, telephonists and secretaries. However female clerks would earn less than one third of the male wage, and a female typist would earn i1 a week compared to i3 a week earned by a man. Women from the upper and middle classes came to have more opportunities in the late nineteenth century. This was particularly so in education. Higher education was open to women, although they were restricted in taking degrees in either Oxford or Cambridge. Most women lacked such opportunities. Women mainly moved into the low-skill, low-pay ‘sweat shop' sector as they were denied access to the new technologies. Female factory workers were generally worse treated than men in pay, training and opportunities, and the trade unions mainly male organisations co-operated with the management or the definition of skills, which affected pay, were controlled by men and favoured them; skilled women were poorly recognised. Women were also paid piece rates and found their wage lowered if they earned too much. One factory inspector remarked that ‘What can one do when a girl is earning as much as 15 shillings a week but lower the piece rate? ‘ In a survey just before the war the social commentator and reformer, S. Rowntree, had argued that i1 a week was necessary in order to live above poverty but few women received this amount. In J. M Barrie's comedy What Ever Woman Knows (1908), John Shand, the railwayman turned MP, owes his success as a debater to his wife Maggie, who has transformed his boring speeches when she typed them up. Women had achieved some degree of marital equality and been given some educational opportunities by 1914. They had also begun to make some inroads into traditional male occupations and they had focused political action on winning the vote.

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