Friday, December 27, 2019
Teaching Speaking - 1667 Words
Teaching speaking skills 2 - overcoming classroom problems Submitted by TE Editor on 16 February, 2004 - 13:00 This article is written for teachers with large classes of students who have encountered some of the following or similar problems during speaking activities in their classroom. * Why should we teach speaking skills in the classroom? * Motivation * Speaking is fundamental to human communication * Dealing with the arguments against teaching speaking skills * Students wont talk or say anything * When students work in pairs or groups they just end up chatting in their own language * When all the students speak together it gets too noisy and out of hand and I lose control of the classroom *â⬠¦show more contentâ⬠¦If you are shy about speaking in English, how can you expect your students to overcome their fears about speaking English? Dont worry if you are not completely fluent or dont have that elusive perfect native accent, as Swain (1985) wrote We learn to speak by speaking and that goes for teachers as well as students. The more you practise the more you will improve your own o ral skills as well as help your students improve theirs. When students work in pairs or groups they just end up chatting in their own language. Is the activity or task pitched at the right level for the students? Make sure you give the students all the tools and language they need to be able to complete the task. If the language is pitched too high they may revert to their L1, likewise if the task is too easy they may get bored and revert to their L1. Also, be aware of the fact that some students especially beginners, will often use their L1 as an emotional support at first, translating everything word for word to check they have understood the task before attempting to speak. In the case of these students simply be patient as most likely once their confidence grows in using English their dependence on using their L1 will begin to disappear. Are all the students actively involved and is the activity interesting? If students do not have something to say or do, or dont feel the need to speak,Show MoreRelatedTHE USING OF COMMUNICATIVE LANGUAGE TEACHING APPROACH IN TEACHING SPEAKING3075 Words à |à 13 PagesTHE USING OF COMMUNICATIVE LANGUAGE TEACHING APPROACH IN TEACHING SPEAKING Markus Dimu Radja ABSTRACT In teaching speaking teachers should know a).the concept of speaking, the element of the sound for instance phonemes because some of the students and including teachers still find difficulties in pronouncing them and b).models of learning and teaching and focused on CLT . Common to all version of Communicative Language Teaching is a theory of language teaching that stars from a communicative modelRead MoreSpeaking And Writing Based Language Teaching843 Words à |à 4 PagesWith Task-based Language Teaching (TBLT) language teaching is accomplished through tasks which have a specified result or outcome. Further to that, students should be clear on the purpose of the task and the expected outcome. In TBLT, teachers define and guide the tasks and model the correct language forms however, student self-correction is desired. Evaluation is through task completion and presentation. With the use of TBLT, the types of tasks selected can be categorized as focused vs. unfocusedRead MoreWhy Abt Is Effective For Teaching Speaking At Clt Classroom Essay2031 Words à |à 9 PagesThe first question of this research is asking if ABT is effective in teaching speaking in CLT Classroom. In answering the question, the Paired Sample T Test was used. The result can be seen in the following table 5.1: Table 4.1 The Analysis of the Pre- Activities and Post- Activities in the experimental group by using t- test Paired Sample Statistic Paired Samples Statistics Mean N Std. Deviation Std. Error Mean Pair 1 Post-test of ABT + CLT) 101.73 30 8.034 1.467 Pre-test of ABT + CLT) 89.97Read MoreTeaching Reading Fluency For Arabic Speaking English Language Learner Students797 Words à |à 4 Pagesread is The Effectiveness of Direct instruction In Increasing English Reading Fluency For Arabic Speaking English Language Learner Students In Qatar; A Research Case Study, by Jared Lorence. Arabic being my second language, this article was a real interest to me. Many of the students I teach ELL or not are influenced by the Arabic language in their daily life. Seeing how teachers in Qatar are teaching their children, in my opinion can be very helpful for a teacher in the USA because they are nowRead MoreTeaching Hel Is The Variation Of Language And Give Voice Of Ordinary People Speaking796 Words à |à 4 PagesOur approach to teaching HEL is to embrace the variation of language and give voice to ordinary people speaking these variants. While we must rely on textual documentation for most historical samples, we do have recordings of older spea kers in American English that continue to exhibit some of the same dialect features found in early Englishes. These voices are found in the interview data collected for the Dictionary of American Regional English, a six-volume dictionary of regional American EnglishRead MoreEnglish As The World Language819 Words à |à 4 Pagesin society, studying aboard has become more and more popular. Not only because of English as the world language is an agent to connect countries, but also speaking English fluently will be beneficial for the future personal development. In order to study oversea smoothly, the first step is to go through the language--English. Generally speaking, English has been divided into two different types according to the purposes which are English for Academic Purpose (EAP) and General English (GE). It is obviousRead MoreThe Abraham Friedman Occupational Center889 Words à |à 4 PagesThroughout the program, my placement was set at the Abraham Friedman Occupational Ce nter. The students were predominantly Spanish-speaking adults who lived in downtown Los Angeles. The program was ESL Intermediate High B that integrated language skills. Since October last year, I devoted seventy hours to observation and taught four lessons totaling five hours. The guiding teacher Mr. Buckley was an inspiring educator who created a variety of classroom activities. Analysis I benefited from the observationRead MoreThe Delivery Of Communication And Differentiated Instruction772 Words à |à 4 Pages Although using different teaching strategies is necessary in a differentiated music class, simply using them is not necessarily differentiating instruction. I like to think of strategies as the delivery of communication and differentiated instruction as the specific individual implementation of strategies. For example in a music class, one of my strategies of keeping students engaged is to use simple percussion instruments for developing rhythmic proficiency. The differentiated instruction is providedRead MoreTraditional Teaching Method Versus New Teaching Method1262 Words à |à 6 Pagesgenerations which are considered the drive to innovation, social and economical growth (Damodharan Rengarajan 07). As mentioned by Damodharan and Rengarajan, the measure of efficiency in teaching narrows down to the methodology used in the teaching system. Frankly speaking, if we consider the available methods for teaching, the debate will definitely occur between the traditional teacher-centered systems versus more contemporary student ââ¬â centered approach. Being told what to do to get an A is not simplyRead MoreWriting Assignment : Education ( Test )1269 Words à |à 6 Pagesis used in the Zen-style teaching method. Moriââ¬â¢s input and familiarity with the Zen-style teaching method follows truly with how David Sedaris in, Me Talk Pretty One Day, found his point of enlightenment. The marvelous feeling of reaching enlightenment comes purely from the effort and speed at which you perform a certain task; from understanding someone to mastering a skill, the end result marks a beneficial use of the time you put into that task. The Zen monkââ¬â¢s teaching techniques used in Japan
Thursday, December 19, 2019
The Problem Of The Soul - 1086 Words
Flanagan, a naturalist, asserts in his book The Problem of the Soul that he is an atheist on the concept of the soul and he is a quietist when it comes to the concept of god. What he means by this, is that he does not believe in the existence of the soul, for several reasons, and believes that we shouldnââ¬â¢t be discussing the concept of god in general because while he admits that it is logically plausible, there is no way that we can ever know if god exists or not for absolute certain. Flanagan states that what he means by the title of his book is, ââ¬Å"â⬠¦ a shorthand was of referring to a cluster of philosophical concepts that are central components of the dominant humanistic imageâ⬠and that these ââ¬Ëproblemsââ¬â¢ of the soul primarily include, ââ¬Å"... a nonphysical mind, free will, and a permanent, abiding, and immutable self or soul.â⬠The central theme of the book is the obsoleteness of the humanistic image as well as its utter incompatibility wit h the logical, empirically supported scientific image. Flanagan argues that the humanistic and scientific images are in no way compatible, and that we should all throw out the humanistic image and instead adopt the scientific image. One of the fundamental bases of the humanistic image, is that we humans are not completely animal. The humanistic image asserts that since we were made in godââ¬â¢s image, we are somehow above the rest of the animal kingdom and consequently possess the magical powers that constitute Flanaganââ¬â¢s Problem of the Soul.Show MoreRelatedPlatos Soul and the Homunculus Problem1745 Words à |à 7 PagesPlatoââ¬â¢s Theory of Soul and The Homunculus Problem Rebecca Vinci Platoââ¬â¢s theory of the soul and the Homunculus theory of human cognition are two distinct theories that both allude to the concept of a mind having smaller parts within it that are assigned to certain tasks and each responsible for the function of a certain cognitive capacity which, together, explain some aspect of the functioning of the whole Both theories use this cognitivist concept as an attempt to explain the complexity of the humanRead MoreThe Oldest, Wicked Problem : Reflections Of An Old Soul Essay2247 Words à |à 9 PagesWicked Problem: Reflections of an Old Soul Growing up, I never quite fit in with my peer group. This was due to a variety of factors which include, but are not limited to, my sexuality, my quirky personality, and my physical disabilities. However, one of the most impactful reasons I have related more to older people rather than my own peer group stems from what many consider to be the concept of an ââ¬Å"old soulâ⬠. This paper will elaborate on this concept, and how it relates to my wicked problem of ageismRead MorePersonal Identity : The Black Rose Killer988 Words à |à 4 Pageshe is the same person and same soul, but is he really the same identity? He lives the life of two completely different people and does completely different things with those two different personalities. Mark Rowlandââ¬â¢s essay of Personal Identity ties in perfectly with Brother Edward. Brother Edward is a person who would be a perfect applicant for theory of personal identity. According to Mark Rowlandââ¬â¢s soul theory, each one of us is essentially a soul and this soul is stuck with us in our body foreverRead MoreSelf-Identity Qualities1010 Words à |à 4 Pagesbe attributed to oneââ¬â¢s ââ¬Å"samenessâ⬠? I have arrived at the problem of self-identity, what makes one person the same over time? I assert that in addition to the presence of unique physical and mental substance, in each person is a constant factor that cannot be altered. I shall show that the problem of self-identity is solved with both the existence of a soul as well as psychological makeup; X is the same as Y so long as X possesses the same soul, body and consciousness as Y. Descartes theory of dualismRead MorePersonal Identity: Philosophical Views1414 Words à |à 6 Pages(body) perspectives. There are several general philosophical theories of this identity problem. In the following paragraphs one will find the body theory, soul theory, and a more detailed explanation of the conscious theory. One theory of personal identity is known as the body theory. This is defined as a person X has a personal identity if and only if they have the same body Y. However there are two problems with this definition. The first is qualitative. It is necessary to have the same bodyRead MoreEssay about Personal Identity: Philosophical Views1404 Words à |à 6 Pagesperspectives. There are several general philosophical theories of this identity problem. In the following paragraphs one will find the body theory, soul theory, and a more detailed explanation of the conscious theory. nbsp;nbsp;nbsp;nbsp;nbsp;One theory of personal identity is known as the body theory. This is defined as a person X has a personal identity if and only if they have the same body Y. However there are two problems with this definition. The first is qualitative. It is necessary to haveRead MoreThe Only Way Out in Richard Millerà ´s The Dark Night of the Soul 1181 Words à |à 5 Pagesof The Dark Night of the Soul, is an English professor/executive director of the Plan-genre Writing Center at Rutgers University. He studies the English curriculum in the U.S and questions if it is successful or a dying art. This is evident in The Dark night of the Soul, It can be quite a shock to confront the possibility that reading, writing, and talking exercise almost none of the powers we regularly attribute to them in our favorite stories. The dark night of the soul for literacy workers comesRead MoreThe Neural Basis Of Free Will : Criterial Causation Essay1523 Words à |à 7 Pagesat. If this argument is indeed as true as it appears to be, then it would seem to provide a valid solution to the hole in Nahmiasââ¬â¢s argument in several ways. First, the core assumption made by the scientific definition is that free will requires a soul or immaterial mind. The criterial causation argument appears to present a valid method of having free will without featuring either aspect of that definition. Secondly, this argument presents a form of having free will within the neuroscientific realmRead MoreSocrates Virtuous Soul Analysis1234 Words à |à 5 PagesThis philosophy study will argue against Socratesââ¬â¢ ââ¬Å"virtuous soulâ⬠as the mot ivation for just acts in The Republic. Socratesââ¬â¢ argument for the ââ¬Å"balanced soulâ⬠as a motivation for just acts is defined in relation to the contrasting arguments of his contemporaries, such as Thrasymachus, Glaucon, and Adeimantus. This ideological view of the ââ¬Å"virtuous soulâ⬠does not provide a practical explanation for the motivation of a ââ¬Å"just actâ⬠in a hierarchical society. The argument of Thrasymachus defines justiceRead MoreThe Mind Is An Immaterial Soul Essay1139 Words à |à 5 Pages In this paper I will refute the view that the mind is an immaterial soul by highlighting how substance dualism lacks explanatory power. To successfully dismantle the contentions offered by substance dualism, I will present two arguments illustrating how ineffectual this theory is at explaining everyday phenomena. My intention in doing so is to stress how theories that lack explanatory power in comparison to other, more robust, theories can be generally regarded as weaker. Once my arguments have
Wednesday, December 11, 2019
The Environment Essay Example For Students
The Environment Essay The EnvironmentThe impact of people on their environment can be devastating. This is where the respective role of governments can make decisions that shape environmental policy and responsibilities. These governments can be broken up into four different levels: local, state, federal and international. Air quality and biodiversity are two current issues that can be related to the role of governments. Global warming is also another implication that has a devastating effect on the environment. Current examples include the rise in sea levels, polar meltdowns, the melting of ice sheets and glaciers and human deaths due to disease from the effects of global warming. Firstly the environment can be defined as the natural features of our surroundings such as plant and animal life and their habitats, water, soils and the atmosphere. A local government named Rockdale Municipal Council has implemented certain actions to deal with the quality in that region. They have recognized that the main sou rce of poor air quality originates from air pollution sources such as motor vehicles, industrial premises and aircraft emissions. The solutions to these problems include improvements to Ryde and Botany Bay cycle way, integration of land use and transport planning strategies, production of Air Quality the Facts booklet for community, investigation of complaints regarding odours and dust, tree planting and preparation of a Local Air Quality Management Plan in 1999. Air quality is a major issue in most states within Australia that affects our greenhouse, to tackle the implications state governments have created policies and responsibilities. For instance Cities for Climate Protection (CCP) is a program that enables mainly state governments to take action on greenhouse. CCP provides these state governments with a strategic framework to diminish greenhouse gas emissions by helping them identify and recognize the emissions of their council and community, set a reduction goal and develop and utilize an action plan to reach that goal. State actions include: capturing the methane from landfill sites and public and non-car transport into urban planning. On a federal or national basis Australia has employed policies to increase the air quality. For example the Commonwealth Government will guarantee that Australia carries its fair-share of the burden in worldwide efforts to combat global air pollution through policy development and implementation. They have also supported the National Greenhouse Strategy (NGS) which began in late 1996. The government will also support the development of a national strategy to observe and manage air toxics. The air toxics strategy will monitor, establish the levels of community exposure to, and manage emissions of selected air toxics. The federal government will even consider the inclusion of air toxics in a future National Environmental Protection Measure. Further measures include the leading of the development of national ambient air qu ality standards through the National Environmental Protection Council and the assistance of the establishment of a National Pollutant Inventory which will require large companies to publicly report their emission of 90 pollutants. Local government Rockdale Municipal Council has introduced responsibilities and policies to reduce the loss of biodiversity. This local government has learned that the cause involves the introduction of species, pollution of land and water, weed invasion and urban encroachment. Their solutions to these problems comprise of the planting of over 3,500 plants and shrubs in Bardwell Valley and Scotts Reserve, bush regeneration and planting in Scarborough Reserve, involvement in Cooks River Foreshores Working Party and preparation of a flora and fauna study in 2000. Policies towards the community include controlling noxious weeds on your property, planting native trees indigenous to the area and applying to the council prior to removing any trees. The Labor Tasmanian Government has created a new Environment Policy on biodiversity that hopes to preserve native plants and animals. The policies commit the government to encourage community involvement in biological diversity programs, proclaim the Tasman National Park, establish a State Biodiversity Committee with community representation to arrange a Tasmanian Biodiversity Strategy, support the development of a State Policy on the protection of remnant native vegetation, examine the possibility of incorporating the Biodiversity Strategy into legislation and seeking the co-operation of local government and the community in including and enforcing biological diversity guidelines in development criteria. Time management EssayMelting is taking on vast and unprecedented level in the Arctic sea ice, the Antarctic and in dozens of mountain and sub-polar glaciers, and the rate has accelerated immensely in the past decade. The Earths ice cover could have intense changes on the global climate and rising sea levels could start regional flooding. Melting of mountain glaciers could also endanger urban water supplies and the habitats of plant and animal species in fragile environments. Within the next 35 years, the Himalayan glacial area is expected to shrink by one-fifth, to just 100, 000 kilometres. A prediction forecasts that the remaining glaciers could disappear in 30 years. The melting has been especially noticeable in the past three decades, and scientists believe that it is the result of human behaviour and the build up of carbon dioxide and other greenhouse gases that contribute to global warming. All current examples of global warming are significant due to the effects that it has on the environment and people. For people, it can cause infectious diseases and pollution-related illnesses that in turn effect our standard of living. Some examples can be more significant than others. For example diseases amongst people is more so important than the rise in sea levels and melting of glaciers since peoples existence are endangered. Environment Essays
Wednesday, December 4, 2019
Laboratory Techniques and Measurements free essay sample
Abstract:There were several objectives in this experiment that allowed student to familiarize themselves with different techniques used a laboratory environment. Students were instructed to conduct measurements such as length, mass, temperature, volume, and density using common tools. Dilutions were also created during this experiment, and then calculated using basic algebraic formulae. This experiment allowed students to become proficient in using utensils in the lab, and in conducting basic measurements. Experiment and Observations: Length Measurements In this experiment, students were required to measure three objects with a ruler showing and record the data in the table below, approximating to one decimal place. Object Measured Length in cm Length in mm Babyââ¬â¢s bottle 14. 2 cm 142 mm Pen 14. 5 cm 145 mm Diameter of the opening of a glass 8. 4 cm 84 mm Temperature Measurements There were two temperature measurements: warm and cold. Students were instructed to measure the temperature of hot water in three stages: hot from the sink, the temperature at the boiling point, and finally, the temperature after boiling the water for 5 minutes. We will write a custom essay sample on Laboratory Techniques and Measurements or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Afterwards, students were directed to measure the temperature of cold water in three stages: cold water from the tap, temperature of water after adding ice cubes, and finally the temperature of the same water after 5 minutes. Students were required to add the data in the table below. The measurements were done in Celsius. Hot water from tap (C0) Boiling water (C0) Boiling water after 5 minutes (C0) 54 C0 93 C0 95 C0 Cold water from tap (C0) Ice water (C0) Ice water after 5 minutes (C0) 22 C0 18 C0 5 C0 Volume Measurement In this experiment students were instructed to measure the volume of the water after filling a test tube, and then pouring the content into a 25mL graduated cylinder. The volume was to be recorded in the table below. In the next step, students were required to measure the volume of a thin-stemmed pipet, by filling it with water, then adding this water into the graduated cylinder one drop at a time, until the 1mL mark was reached. The number of drops used were added to the table below. Finally, students had to empty the content of the pipet into the graduated cylinder, and they were instructed to write the volume of the water from the graduated cylinder into the same table. The measurements were recorded in mL. Volume of test tube (mL) Number of drops in 1 mL Volume of pipet (mL) 12 mL 25 drops 5 mL Mass Measurement For this experiment, a digital scale was used. Students were instructed to use the correct tare in order to reduce inaccuracies. Students were required to try to guess the masses of these objects, and add their estimates into the table below. Afterwards, they were instructed to weigh the objects, and record their actual masses into the same table. Measurements were recorded in grams. Object Estimated Mass of Object (g) Actual Mass of Object (g) Vitamin pill 0. 5 g 0. 6 g Empty plastic measuring cup 5 g 25. 8 g Container filled with garlic powder 200 g 271. 8 g Container filled with toothpicks 153 g 51 g Plastic container, filled ? of the way with parsley 25 g 24. 2g The lid of the scale used in this experiment 10 g 10. 1 g Wedding ring 5 g 3. 1 g Density Measurements In this section, several methods were used to measure densities. 1. Calculating densities using a scale, a graduated cylinder, and the formula: density = mass/volume In the first step, students were required to determine the density of water, using a graduated cylinder, a small scale, and the density formula: density=mass/volume. These measurements were recorded in the table below. In the next step, students measured the density of isopropyl alcohol through a similar method they measured the density of water. In the following step, students were required to measure the density of salt solution through similar methods. After measuring the mass of 5 mL of the salt solution, they were required to form a hypothesis on whether the density of this solution is higher or lower than that of water. The actual measurements were recorded in the table below. Hypothesis: the density of the salt solution would be greater than the density of water, because the mass of the salt solution is greater than that of the water, and when two fractions have the same number in the denominator (5), but the numerators are different, the fraction with the higher numerator will be the greater of the two. Mass A Mass B Mass A-B Object Graduated cylinder + substance Graduated cylinder Substance Density (M/V) Water 21. 8 g 17. 2 g 4. 6 g 0. 9 g/mL Isopropyl alcohol 21. 5 g 17. 2 g 4. 3 g 0. 9 g/mL Saturated salt solution 22. 6 g 17. 2 g 5. 4 g 1. 1 g/mL In the next step, students were required to compare two different techniques of measuring density. 2. Water-displacement method In this experiment, students had to calculate the density of a metal bolt and a magnet using the water-displacement method. The data gathered was entered in the table below. 3. Archimedesââ¬â¢ method In this experiment, students were instructed to calculate the density of the same metal bolt and magnet via Archimedesââ¬â¢ method. 4. Math calculations method Once the comparisons between the above mentioned techniques were completed, students were required to use the math calculations method to determine the density of the magnet. Since the magnet has measurable sides, this is a viable technique. A B B-A Object Graduated cylinder volume Graduated cylinder + object Object volume (mL) Object mass (g) Density (M/V) Metal bolt: water-displacement method 12. 5 mL 13. 5 mL 1. 0 mL 8. 0 g 8. 0 g/mL Metal-bolt: Archimedesââ¬â¢ method 1. 0 mL 8. 0 g 8. 0 g/mL Magnet: water-displacement method 12. 5 mL 13. 5 mL 1. 0 mL 4. 3 g 4. 3 g/mL Magnet: Archimedesââ¬â¢ method 1. 0 mL 4. 3 g 4. 3 g/mL Magnet: math calculation method 0. 8 mL 4. 0 g 5. 0 g/mL Making a Dilute Solution While these steps didnââ¬â¢t require students to collect data into a table, they were instructed to perform certain tasks in order for them to learn how to use certain laboratory tools in order to prepare accurate dilute solutions. The instruments required for this exercise were a 0. 2 mL serological pipet with bulb and a 100 mL beaker. The students squeezed the bulb and placed the tip of the pipet into the beaker. When they released the bulb, they collected enough liquid to reach the 0 mark. Students then released 1. 0 mL liquid from the pipet, then an additional 0. 5, and finally the entire 2. 0 mL liquid. In the following portion of the lab, students were required to observe a volumetric flask, which only measured 25mL volume (quantum sufficit) indicated by a line. Using the serological pipet, students delivered 5 mL of colored liquid into the volumetric flask. The rest of the flask was filled with water up to the 25 mL mark. I used prune juice, which has a reddish-brown color. When I added the water to it, the liquid became lighter reddish-brown color. Still, the mixture wasnââ¬â¢t uniform. Most of the juice collected to the bottom of the flask, and the color gradually faded up to the 25 mL line. Calculations and Error When calculating the length of an object, errors in measurements were minimal, because the ruler was marked to millimeters. This ensured the margin of error was reduced. Had students used a ruler with only inches marked, the error would have been greater. Measuring the temperature was straight forward. I just had to ensure I kept the thermometer straight. The water boiled at less than 100 C0, and didnââ¬â¢t reach that temperature even after 5 minutes. The cold water did not reach the 0 C0, even with the ice in it. These measurements were taken with a mercury thermometer, which are considered accurate. More accuracy could have been achieved by measuring the temperature with multiple thermometers. Measuring the volume in the graduated cylinder was also fairly accurate, because it was clearly marked. The design of test tube allowed me to fill it up completely. The chances of errors was slightly higher in this part of the experiment, due to the difficulty in adding an exact amount of fluid into the cylinder. 1-2 extra drops could make a difference. I attempted to measure by adding the liquids to where they were in one plane with the 5 mL mark. The degree of error when measuring the number of drops in 1 mL was larger due to the possibility of the drops having different sizes. Smaller drops would have been needed to fill the cylinder to the 1mL line than smaller drops. The margin of error when measuring mass was decreased significantly by adjusting the tare appropriately, and using the same scale for every measurement. As shown in the table, most of the time, the actual measurement differed quite a bit from the hypothesized mass. For the measurement of density the following formula was used: density=mass/volume Density of water: 4. 6g/5mL = 0. 9 g/mL Density of isopropyl alcohol: 4. 3g/5mL = 0. 9 g/mL Density of salt solution: 5. 4g/5mL = 1. 1 g/mL Measuring the density of liquids yielded some errors. If rounded to two decimal places, water had a density of 0. 92 g/mL, and isopropyl alcohol had a density of 0. 86. This would have been more accurate, than the data actually entered into the table. Based on rounding requirements stating that the decimal places of the product should match the lowest decimal place of the numerator and denominator, I had to round to only one decimal place. If rounded to one decimal place, water and isopropyl alcohol would show the same density, but the density of isopropyl alcohol is slightly lower than that of water. Measuring the density of objects yielded the same result in water-displacement test and the Archimedesââ¬â¢ method. Both had their own challenges. When using the water displacement method, students had to ensure that the water level was read accurately. With Archimedesââ¬â¢ method, students had to ensure the scale was appropriately calibrated, and they had to ensure the objects werenââ¬â¢t touching the side of the beaker. Based on the data gathered, both yielded similar results. Water displacement method calculation for both the bolt and the magnet used was similar. The volume of water in the graded cylinder was 12. 5 mL in both instances. When dropping the bolt into the cylinder, the volume read 13. 5 mL. The same volume was recorded when the magnet was dropped into the cylinder. In order to determine the water displacement, the students had to subtract the volume of the water from the volume of the water when the object was in it. For the both objects, 13. 5g-12. 5 g=1. 0g. The weight of the bolt was 8. 0g, and the weight of the magnet was 4. 3 g. As such, the data recorded for the bolt was: density = 8. 0 g/1. 0 mL = 8. 0 g/mL, and density of the magnet was: 4. 3 g/1. 0 mL = 4. 3 g. For the Archimedesââ¬â¢ method, I used the scale. This method was easier, but the possibility of errors was greater, because I had to have a steady hand. I filled a beaker with water to the 50mL line, and placed it on the scale, then ensured the tare was set to 0. 0g. Slowly, I submerged the objects using a string, and the weight measured on the scale showed the density. I gathered the same results as in the water displacement test: density of the bolt: 8. 0 g/mL, and the density of the magnet was 4. 3 g/mL. Using the mathematical method yielded a different result. The volume had to be calculated using the measurements of the three sides. The value had to be converted into mL, and the mass had to be divided by the volume. Mass of magnet: 4. 3 g, volume of magnet = 5mm x 6mm x 25mm = 750 mm3 = 0. 750 mL. Density = 4. 3g/0. 750 mL = 5. 7 g/mL. Discussion and Conclusion The measurement for the length was straight-forward. There wasnââ¬â¢t too much of a margin for error. All the objects I measured were the exact length I added into the table. I didnââ¬â¢t measure any objects that ended between the millimeter marks. One might argue that the babyââ¬â¢s bottle would be more difficult to measure, and measuring this object would yield the most errors, because of the shape of the object. Using a pen to connect the top of the bottle to the ruler alleviated much of this error, and allowed me to have an accurate reading for the length. Due to the design of test tubes, I was able to fill it all the way with the water, and this yielded accurate results when measuring its volume in the graded cylinder. Filling the pipet was a bit of a task until I found the right trick to it. Counting the drops seemed somewhat subjective, because it depended on how big the drops were. The instructions did not state how bid the drops should be. One way to alleviate this error would be to describe the size of drops. Or, an even better way would be to use a pipet that is less flexible, and has standard drops flowing from it. As mentioned in the ââ¬Å"Errors and Calculationsâ⬠section, measuring temperature with an alcohol thermometer was fairly accurate. The degree of accuracy could have been known if the temperatures had been taken with multiple thermometers. I expected the water to boil at less than 100 C0, because the house was above sea level, closer to Denver, CO. I did expect the water to reach that temperature after 5 minutes, but it didnââ¬â¢t. It seemed to cap out at 96 C0. My expectations were similar to the outcome when measuring the temperature of the cold water. I did not expect it to reach 0 C0, because there was plenty of liquid water in addition to the ice, even after 5 minutes. It was interesting to note the difference between the hypothesized mass, and the actual mass measured with the scale. In some cases, I was only a tad off, while in other cases, I was very off. The degree of accuracy was questionable. It was based on the fact that I faith that the scale was calibrated properly. I did adjust the tare accordingly, but in order to ensure a better degree of accuracy, I could have weighed each object on multiple scales. I already knew the density of water, and as a result, I was happy to see that my measurements were accurate. Still, when measuring the isopropyl alcohol, if rounding to only one decimal place, the density was the same as that of water. Of course, when rounding to two decimal places, the rubbing alcohol was slightly less dense than water, at 0. 86 g/mL versus 0. 92 g/mL. Rounding to more than one decimal place increased the accuracy. I expected the density of the salt solution to be higher, because the mass of the solution would increase compared to just water. Just as I had predicted, the density of the salt solution was 1. 1 g/mL. Measuring the densities with the water displacement vs the Archimedesââ¬â¢ method was surprisingly similar. I expected to see at least a slight difference, but both yielded the same results. The density of the bolt was 8. 0 g/mL, and the density of the magnet was 4. 3 g/mL. I could see based on these results why Archimedesââ¬â¢ method was accurate. Both methods required much precision. I had to ensure the scale was calibrated properly, and that my hands werenââ¬â¢t moving frantically while lowering the objects into the beaker. Based on these results, both measurements proved to be accurate. The mathematical method yielded some issues. The result was very different from the above methods. I even converted mm3 to mL to ensure accuracy. Still, the result was surprisingly different. The density was 5. 0 g/mL. I added details on how I completed the calculations in the ââ¬Å"Calculations and Errorsâ⬠section. I was trying to devise different theories behind the discrepancies. I was thinking that it may have been that the length measurements had nothing to do with the actual material. We had to calculate the volume based on the length, height and width. This yielded 750 mm3, which is 0. 75 mL. The objectââ¬â¢s density then would be 4. 3 g/0. 75 mL=5. 7 g/mL . Although the results were identical when measuring with the water displacement method and Archimedesââ¬â¢ method, these two methods are not always accurate. The cylinder might be calibrated differently, water might spill when the object is drooped in it. Archimedesââ¬â¢ method can also be inaccurate. If the water or the hand moves, the numbers start changing on the scale. The mathematical calculation method is considered to be the most accurate, if the object has definite sides. Creating the mixture was fun, but based on the fact that the pipet can have hair bubbles trapped, I had to be very careful. One air bubble could throw off the entire experiment. Because I used prune juice, it all tended to gather on the bottom of the flask. I was still able to see the juice disperse in the water, and the closer to the 25 mL mark, the lighter the color of the liquid. I didnââ¬â¢t think that the consistency of the juice was different, so I expected for the juice to evenly mix in the water. I was proven wrong by the experiment. Questions A. The water did boil at a lower temperature, because the experiment was conducted above sea level. The reason for this is that there is less atmospheric pressure at higher altitudes. Less pressure requires energy. B. The percent error is calculated with the following equation: 100 x(|experimental value-theoretical value|/theoretical value) |102-100| 100 x = 100 x 0. 02 = 2% For water boiling at 1020C 100 |99. 2-100| 100 x = 100 x 0. 08 = 8% For water boiling at 99. 20 100 C. First, we calculate the volume: 3. 6 cm x 4. 21 cm x 1. 17 cm = 17. 7 cm3 If we want the density in g/mL, we convert 17. 7 cm3 to mL, which is 17. 7 mL. Second, we determine the mass of the object, which is 21. 3 g. The density is found by dividing the mass by the volume. D=mass/volume D=21. 3 g/17. 7 mL = 1. 2 g/mL D. Density=mass/volume as a result Volume=mass/density The Au sample has a mass of 26. 15 g The density of the sample is 19. 30 g/mL Volume = 26. 15 g / 19. 30 g/mL Volume = 1. 35 mL E. This is a difficult question to answer, because based on my experiment, both methods were equally accurate. It depends on the object that is being experimented upon on, the tools used within the experiment, and the person completing the experiment. For example, for the bolt it would be easier to just use Archimedesââ¬â¢ method, because it is easy to just get a string, tie it on the bolt, and submerge it into the water. With the magnet it may be more beneficial to use the water displacement method, because the string might fall off. If one doesnââ¬â¢t have steady hands, it is more beneficial for them to use the water displacement method. I believe it is a matter of preference and also a matter of what resources one has available. F. If one dropped the object into the beaker the measurements would be incorrect. The experiment specifically states not to touch the bottom or the sides of the beaker. It is important to complete the experiment gently. G. Although I got similar results when using Archimedesââ¬â¢ method as when I used the water displacement technique, there is more room for error when using Archimedesââ¬â¢ method. The hands need to be perfectly still, without the water touching the beaker. Plus, the experimenter has to ensure the scale is calibrated properly. H. In this exercise, we can determine the density, because we have the volume and the mass. Volume = 0. 40 cm3 = 0. 40 mL Mass= 6. 0 g Density = mass/volume Density = 6. 0 g/0. 40 mL = 15 g/mL The density of gold is 19. 3 g/mL. As a result, this object is not made of gold. I. First, we convert 0. 25M to moles/L 0. 25M=0. 25 moles/L In order to determine how many moles of HCl we need, we have to multiply the 10mL by . 25mol/1000L. 10*(0. 25mol/1000L)=0. 0025mol In order to determine how much 1M HCl solution one should use, we have to multiply the 0. 0025 mol by 1000mL/1. 0 mol HCl 0. 0025 mol *(1000mL/1. 0 mol HCl) = 2. 5 mL Since we have 10 mL of solution, and 2. 5 mL of HCl, the amount of water used is 10 mL-2. 5 mL = 7. 5 mL. J. Using molarity to express concentration: Original liquid: 2. 43 M Volume of solution = 25. 0 mL = 0. 025L 2. 43 M = 2. 43 moles/L Molarity = moles of solute/volume of solution Molarity = (2. 43 moles/L)/0. 025L Molarity = 97. 2 M K. The color after diluting is lighter, because it is less concentrated. The reason for the dilution is to make the original liquid less concentrated. The more the liquid is diluted, the lighter in color it gets. M. When diluting a liquid, the color gets lighter, the more water we add. The reason for this is the fact that the original liquid becomes less concentrated. The more water add, the more the original liquid disburses throughout the water. N. The water will boil faster in Colorado. The reason behind it is the difference in atmospheric pressure between seal level and high altitudes. The lower the pressure, the less energy is required to boil the water. Based on the experiment, the water started boiling at around 920 C, and it didnââ¬â¢t reach 1000C even after 5 minutes. O. 1. Calculating the change: 4. 521g/(13. 534 g/cm3-13. 472 g/cm3) = 72. 919 cm3 (72. 919 cm3)/(? 0. 0252 cm2)=(72. 919cm3)/(3. 1410. 000625cm2)=3. 714105 mm. 2. Calculating the number of atoms of Hg in the thermometer: (4. 521 g)/(200. 592 g/mol)x(6. 0221023 atoms/mol) g and mol cancel out Answer: number of Hg atoms: 1. 357 x 1022 P. 1. V=? r2h Vgold=? (4. 1cm2)(21cm) vgold=1109. 014 cm3 Densitygold =massgold/volumegold Massgold = densitygold x volumegold Massgold = (19. 3 g/cm3)(1109. 014 cm3) Massgold= 21403. 97 g Massgold = 21404 g Vsand = ? (4. 1 cm2)(21 cm) Vsand = 1109. 014 cm3 Densitysand = masssand X volumesand Masssand= densitysand x volumesand Masssand = (3. 0 g/cm3)(1109. 014 cm3) Masssand = 3327. 04 g Masssand = 3327 g 2. The alarm would have been tripped, because the sand is less massive than the gold. Although the volume is identical for both, the density isnââ¬â¢t. Because the density isnââ¬â¢t identical, neither is the mass. In our scenario, the mass wasnââ¬â¢t even comparable. The sand is much less massive than gold. Indiana Jones would have been in big trouble.
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