Find the Ar of lithium Essay Example for Free

Find the Ar of lithium Essay Was my experiment suitable? My experiments enabled me to gain results, which then with the aid of calculations I could find the Ar of lithium. From this perspective you can say the experiment was suitable as I achieved this. Were my results what I expected? Looking at the results they do not match the expected Ar of lithium (6. 9). Method 1, measuring the volume of hydrogen produced, gave the result of 19. 76 (a factor of 12. 86 out). Method 2, titrating the lithium hydroxide produced, gave the result of 8. 65 (a factor of 1. 75 out). So looking at these results not only we can see they are out, but one method is more inaccurate than the other. The titration is far more accurate than the collecting of gas. Comparing both methods, and recognising sources of error. Method1. Sources of error in the collection of gas practical were: When the lithium was weighed I had to place it on filter paper first to remove the oil from it. However I feel that not all of the oil was removed from the Li so perhaps this contributed extra mass which was not part of the Li itself. The scales themselves were awkward to use; when I placed some paper onto the scales and zeroed it (to weigh the Li onto) the mass kept fluctuating, so I was unsure as to how precise my weighing out was. These problems will have both contributed to a source of error- the mass of Li will have not been accurate. The next part of the practical was particularly inaccurate. I had to place the Li into the conical flask and then place the bung onto the flask quick enough so that no gas was leaked. I think this would be virtually impossible. I also had the problem that as I tried to add the Li to the flask, some of the granules stuck to the paper which it was on (probably due to the presence of some oil). So there was a short period where I had to get this Li off the paper and into the flask which will have allowed the gas to escape considerably. For this reason I feel that 60. 6 may be an anomalous result contributing to my highly inaccurate Ar for method 1. When I came to measure the gas evolved itself, my 250 ml measuring cylinder had a small irremovable air bubble inside it. I had no choice to ignore this but again this would have affected my result. Also 250 ml measuring cylinders are only accurate to 2 ml -anything under this had to be estimated, which by its very nature lacks accuracy. Parallax may have been a problem when gauging the volume in the 250ml measuring cylinder (it has a relatively large cross-sectional area compared to a burette). This allows for a greater % inaccuracy if you do not line your eye up correctly with the meniscus. Method2. Sources of error in the titration of lithium hydroxide were: because the Li was not weighed accurately (see above) this would of affected my calculations at the end. Air bubbles in the burette will have affected the titre as will have parallax -this may have been a problem when gauging the volume in the burette (however it has a relatively small cross-sectional area compared to a 250ml measuring cylinder- so is more accurate). But if you do not line your eye up correctly with the meniscus there could be a % inaccuracy. If different batches of acid were used this would have affected the results as well as the concentrations would have been slightly different. Adding Li to the water may have changed the volume also, but I found I had enough to carry out my 4 titrations- just. Another mistake was I left the funnel with which I added the acid in the burette whilst performing the titration. This may have meant extra acid may have been added during the titration. Reliability. I feel that my titrations were reliable as I performed repeats until I had closely matching titres. However I think method 1 was unreliable due to gas loss and in hindsight I would have performed more repeats. Which was more accurate method 1 or method 2? Why was one more accurate than the other? Method 2 (titration) was far more accurate than method 1. This is explained by my above reasons. Far more precise instruments were used in method 2 e. g. a burette instead of a 250ml measuring cylinder. All of my reacting chemicals will have been accounted for in the titration but there was some gas loss in method 1. But if you look at my comparisons you will see there are more serious sources of error in method 1 i. e. placing the bung onto the flask quick enough so that no gas was leaked (no gas involved in method 2) or the fact that 250 ml measuring cylinders are only accurate to 2 ml -anything under this had to be estimated, which by its very nature lacks accuracy (burettes are accurate to 0. 1 ml) etc. Ways to minimise errors, and practical adaptations to improve my experiment.   Reliability could easily be improved for method 1 by performing more repeats (I only did this experiment once! ). I feel method 2 was fairly reliable but again it could be argued that repeats could improve this further.   On method one if you tilt the flask at and angle and place the Li inside so it is not touching the water, and then place the bung and level the tube upwards, the chemicals should mix without gas loss. Also making sure the Li was as pure as possible before weighing to eliminate all oil possible.   Make sure eye is lined with the meniscus and use the smallest instrument possible (with the smallest cross-sectional area possible) to eliminate parallax.   Use instruments with the finest possible gradations to measure volume.   Remove the funnel whilst performing the titration. This will prevent extra acid from being added during the titration   Use the same batch of acid. Then the concentrations will be the same. Air bubbles in the burette removed be titrating.

The American Dream: The Essence of America Essay examples -- Essays on

From the birth of America, to America today, the driving force and the heart of America has always been the â€Å"American Dream.† The â€Å"American Dream† is a goal for many of people who live in the realms of the Americanized world. I believe that the â€Å"American Dream† is controlling my own destiny, becoming successful, and living free. Examples of this dream are things like television, automobiles, supermarkets, malls, Internet, planes, trains, etc. The â€Å"American Dream† is success, freedom, and being able to control your own destiny.   Ã‚  Ã‚  Ã‚  Ã‚  Becoming successful has been the dreams of many people of the past and present and I think that it is one the most important things that a person must accomplish. Anyone and everyone can develop into a successful person, permitting that the person believes i...

Kerja Kursus Addmath

Not forgotten my parent's for providing everything, such as money, to buy anything that are related to this project work and their advise, purport which are the most needed for this project. Internet, books, computers and all that. They also supported me and encouraged me to complete this task so that I will not procrastinate in doing it. Beside that My father teacher at SMS Mat Kills , Kanata Pang, Tn HAJJ Mood Rosalie bin Seine for sharing ideas to ensure our task will finish completely. Then I would like to thank my teacher, for guiding me and my friends throughout this project.We had some difficulties in doing this task, but she taught us patiently until we knew what to do. She tried and tried to teach us until we understand what we supposed to do with the project work.. Last but not least, my friends who were doing this project with me and sharing our ideas. They were helpful that when we combined and discussed together, we had OBJECTIVES The aims of carrying out this project wo rk are: to apply and adapt a variety of problem-solving strategies to solve problems. To improve thinking skills. To promote effective mathematical communication. O develop mathematical knowledge through problem solving that increases students' interest and confidence. In a way to use the language of mathematics to express mathematical ideas precisely. O provide learning environment that stimulates and enhances effective learning. To develop positive attitude towards mathematics INTRODUCTION As a student who takes Additional Mathematics in SUMP, I am required to carry out a project work. This year the Curriculum Development Division, Ministry of Education has prepared two tasks for me.I need to choose one project based on my interest. This project can be done in groups or individually but the students are required to submit an individually written report. Upon completion of the Additional Mathematics Project Work, we are able to gain valuable experiences and able to: Apply and adapt a variety of problem solving strategies to solve routine and non- routine problems; -Experience classroom environment which are challenging, interesting and meaningful and hence improve their thinking skills. Experience classroom environments where knowledge and skills are applied in meaningful ways in solving real-life problems -Experience classroom environments where expressing ones mathematical thinking reasoning and communication are highly encouraged and expected -Experience classroom environment that stimulates and enhances effective learning.Acquire effective mathematical communication through oral and writing; and to use the language of mathematics to express mathematical ideas correctly and precisely -Enhance acquisition of mathematical knowledge and skills through problem-solving -Prepare ourselves for the demand of our future undertakings and in workplace -Realizes that mathematics is an important and powerful tool in solving real-life problems hence develop positive att itude towards mathematics. Train ourselves not only to be independent learners but also to collaborate, doctorate, and to share knowledge in an engaging and healthy environment Use technology especially the CIT appropriately and effectively -Train ourselves to appreciate the intrinsic values of mathematics and to become imperative and innovative -Realize the importance and the beauty of mathematics Part 1 Index numbers 1) An index number is a number that can be used to show changes in magnitude of a quantity over a specific period of time. ) The specific period over which the changes occurred is called the base time. The base usually equals to 100 and thus the index number is usually expressed as a percentage, but the % sign is not usually written. 3) The formula for calculating index of a quantity, I is: Index number, IQ x 100 CO where CO = quantity at base time, IQ = quantity at a specific time. 4) If the index number is 125, it indicates that there is a +25 points or 25% rise of the quantity from base time to the specific time. ) Conversely, if the index number is 97, it indicates that there is a -3 points or 3% fall of the quantity from base time to the specific time. U. S Consumer Price Index – Food and Beverage (it) Weight Weight is common word used in Asia. The meaning for weight is a weighting factor assigned to compensate for perceived advantage or a weight factor or ratio; eight. Weight can also be defined as the importance or value when compared with another thing An example for its usage is: â€Å"The admission holds 80% weight while the interview holds 20% weight of the admission process†.In a nutshell, weight can also be said as stake. Composite Index Composite index is a grouping of equities, indexes and other factors combined in a standardized way, providing a useful statistical measure of overall market or sector performance over time. 1) Unlike index number the index numbers and involves two or more quantities. 2) The weight is the alee or quantity assigned to each item. This terms provide the importance or significance of each quantity. ) The formula of composite index is: Composite index, where = index number for item , = the corresponding weight for item Composite index can also be defined as a group of indices combined to measure the overall price of an item over a period of time. For instance, we can take a look at the price of root canal in the year 2013 based on the year 2010. A composite index may also be used in the natural or social sciences to summarize complex or multidimensional data or redundant measures.Usually, a composite index has a large number of factors which are averaged together to form a product representative of an overall market or sector. For example, the Nasdaq Composite index is a market capitalization-weighted grouping of approximately 5,000 stocks listed on the Nasdaq market. These indexes are useful tools for measuring and tracking price level changes to an entire stock mark et or sector. Therefore, they provide a useful benchmark against which to measure an investor's portfolio. The goal of a well-diversified portfolio is usually to outperform the main composite indexes (b) .Ways of Weight Representations Weight in a set of data can be represented in certain ways. 2) Pie 3) Percentage 4) Ratio part 2 1) Bar Chart We often hear complaints from the public about inflation. It causes an increase in the household expenditure in a family. So what is inflation and how does it affect us in our life? Basically, as citizens, we do get affected as it increases our household expenditure. With that, it will certainly cause problem to low-income families as their expenditure increase but at the same time, their monthly income remains the same.But on the other hand, the capitalists will sure benefit from this situation as they are owners of these large corporations which conduct these businesses. The parties who will be least affected are the middle-class people and the super-rich citizens, I. E. The millionaires. Technically, inflation is caused by the price increase of certain items from time to time. In this part we're going to make a case study on my family household expenditure to investigate this so called â€Å"inflation†

University of Puget Sound Admissions and Admit Rate

Admission to the University of Puget Sound is not highly selective. In 2016, the university had a 79 percent acceptance rate. Successful applicants tend to have high school GPAs above a B and above average standardized test scores (note, however, that ACT and SAT scores are optional).  application, those interested in the University of Puget Sound will need to send in official high school transcripts, a personal essay, and letters of recommendation. For complete information and guidelines about applying, be sure to visit the University of Puget Sounds website, or get in touch with the admissions office. Admissions Data (2016) University of Puget Sound Acceptance Rate: 79 percentGPA, SAT and ACT graph for Puget SoundWhat these SAT numbers meanTop Washington colleges SAT comparisonWhat these ACT numbers meanTop Washington colleges ACT comparison University of Puget Sound Description The University of Puget Sound is grounded in a strong liberal arts curriculum that has earned the college a chapter of the prestigious  Phi Beta Kappa  Honor Society. The University of Puget Sound can boast of an 13 to 1  student / faculty ratio. The school is located in Tacoma, Washington, so students have easy access to the cultural and social opportunities of the city, as well as proximity to the Cascade and Olympic mountain ranges. Students come from 46 states and 8 countries, and on the financial front, the great majority of students receive grant aid. Student life is active with over 100 clubs and organizations, and 23 varsity sports teams that compete in the NCAA Division III Northwest Conference. Enrollment (2016) Total Enrollment: 2,791  (2,508 undergraduates)Gender Breakdown: 40  percent male / 60 percent female99 percent full-time Costs (2016  - 17) Tuition and Fees: $46,552Books: $1,000 (why so much?)Room and Board: $11,800Other Expenses: $2,300Total Cost: $61,652 University of Puget Sound Financial Aid (2015  - 16) Percentage of New Students Receiving Aid: 100 percentPercentage of New Students Receiving Types of AidGrants: 99 percentLoans: 45 percentAverage Amount of AidGrants: $19,322Loans: $8,660 Academic Programs Most Popular Majors:  Art, Biology, Business Administration, Communication Studies, Economics, English, History, Political Science, Psychology, Sociology Graduation, Retention and Transfer Rates First Year Student Retention (full-time students): 86 percentTransfer Out Rate: 16 percent4-Year Graduation Rate: 70 percent6-Year Graduation Rate: 80 percent Intercollegiate Athletic Programs Mens Sports:  Basketball, Crew, Football, Swimming, Cross Country, Tennis, BaseballWomens Sports:  Lacrosse, Softball, Volleyball, Swimming, Golf, Crew, Track and Field Data Source National Center for Educational Statistics If You Like University of Puget Sound, You May Also Like These Schools Reed College: Profile | GPA-SAT-ACT GraphWhitman College: Profile | GPA-SAT-ACT GraphUniversity of Washington: Profile | GPA-SAT-ACT GraphGonzaga University: Profile | GPA-SAT-ACT GraphSanta Clara University: Profile | GPA-SAT-ACT GraphWhitworth University: Profile  Stanford University: Profile | GPA-SAT-ACT GraphLewis Clark College: Profile | GPA-SAT-ACT GraphSeattle University: Profile | GPA-SAT-ACT GraphUniversity of Portland: Profile | GPA-SAT-ACT GraphWashington State University: Profile | GPA-SAT-ACT Graph