Wednesday, January 29, 2020
Chemistry Design Prac Essay Example for Free
Chemistry Design Prac Essay Investigate one chemistry related factor on the deflection of the liquid flow in the presence of a charged rod Research question How will the amount of time spent rubbing a glass rod affect the angle of deflection of flowing water in the presence of the charged glass rod? Background Research Static electricity is formed in contact with two objects, where one object gains electrons from another, resulting in one object having a positive charge while the other having a negative charge. Some materials tend to lose or gain electrons during contact with other objects. Materials with electrons bonded to it weakly, tend to lose electrons while materials with fewer electrons on the outer shell tend to gain electrons. Therefore, when an object is imbalanced of a positive or negative charge, it has static electricity. Polarity is the separation of electric charges, caused when electrons are not equally shared in a molecule. This is caused when some atoms in the molecule have a higher electronegativity than others, causing more electrons to be attracted to it, leaving one side of the molecule more negative than the other. An element or molecule with an electro negativity value of 0.5+ is considered to be polar. When a polar liquid such as water is flowing in a presence of a charged rod, the liquid tend to bend towards the rod. This is because the rod will either be positively or negatively charged, and the dipoles of the polar molecule will be attracted to the charged rod. The charge on the rod is determined by the material which is used to rub against it, however, it does not matter whether the rod is positively or negatively charged because either way, the opposite dipoles of the polar molecule will be attracted towards it, causing the flow of the liquid to bend towards the charged rod. Defining Independent and Dependent Variables Independent The amount of time rubbing the glass rod with a piece of silk. 10 seconds 20 seconds 30 seconds 40 seconds 50 seconds 60 seconds Dependent The angle of deflection of the flowing water will be measured with grid paper with a smallest increment of 1mm. A line will be drawn on the grid paper from the point where the glass rod was places to the point where the water was deflected. A protractor with a smallest increment of 0.5 degrees will be used to calculate the angle of deflection of the water. Controlling Variables Table 1 Variables and Method of control Type Variable Method of Control Controlled The rate of the flow of water Adjust the burette to deliver the smallest stream of water possible but without being discontinuous. The water will be kept flowing at the same rate, throughout the experiment. The glass rod The same glass rod with a diameter of 1cm will be used throughout the experiment. Pressure when rubbing the glass rod Use the same person to rub the glass rod against the silk, applying the same pressure every time. Placement of the glass rod A line will be marked on the grid paper so the glass rod will be placed at the exact point and the exact angle to the flowing water every time. Placement of the grid paper The grid paper will be sticky taped to the burette and placed as close as possible to the flowing water. The same grid paper will be used and left at the same position throughout the experiment. Weather conditions The experiment will be conducted in a room with all windows closed and air conditioning switched off to reduce effects atmospheric effects on the angle of deflection of the water. Stopwatch The one person will be using the same stopwatch every time to reduce systematic errors. Material The same piece of silk cloth (20 cm in length, 15cm in width) will be used throughout the experiment The experimenters The same two people, (person with stopwatch and person controlling the glass rod) will conduct the experiment to keep random errors in measurements and readings consistent. Materials and Equipments List: 50 mL Burette 20cm x 15cm silk cloth 1cm diameter glass rod Distilled water 200 mL Beaker A4 Grid paper with increments of 1mm Protractor with increments of 0.5 degrees Retort Stand clamp Pen Ruler Sticky tape Stop watch Method 1. Attach the clamp to the retort stand. 2. Fill the burette with distilled water to approx 1cm from the top and attach it to the clamp 3. Draw a straight line on the grid paper with a ruler and sticky tape it to the bottom of the burette, lining up the line on the paper exactly with the flow of the water coming out of the burette. 4. Also Draw a line 90 degrees towards the line if the flowing water but stopping at 0.5 cm from the line. This line will be where the charged glass rod will be placed 5. Also mark the origin (the tip of the burette, where the water comes out) on the grid paper 6. Place the 200 mL beaker under the burette and let the water run down 7. Start the timer on the stopwatch and simultaneously, begin rubbing the glass rod against the piece of silk 8. Stop the stop watch at 10 seconds and immediately place the charged rod as close as possible to the line drawn on the grid paper 9. Mark the angle of deflection of the water on the grid paper 10. Wait 1 minute until the rod is completely uncharged 11. Repeat steps 6 9 12. Repeat the experiment from steps 6 10, changing the time rubbing the glass rod against the silk cloth by 20, 30, 40, 50 and 60 seconds. 13. Remove the grid paper and line up all the points of the deflected water to the origin 14. Measure the angles with a protractor and record the results into the table below 15. Pack up the experiment Table 2 Raw data table Time charging the glass rod Angle of deflection of water Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Trial 6 Average 10 seconds 20 seconds 30 seconds 40 seconds 50 seconds 60 seconds Table 3 Risks involved in the experiment and safety precautions to reduce the risks Risk Safety Precaution Action to take The burette is very long and is made of glass and can be broken easily Hold the burette with two hands and always watch for obstacles when carrying around the lab. Wear closed in shoes, lab coat and safety glasses in case the burette breaks. Carefully pick up the large pieces of broken glass one by one and throw in the glass bin. Use a brush to sweep all the small bits into the bin. Make sure there is no remaining broken glass in the lab. Bibliography 1. Columbia University Press (1978-1979). New Illustrated Columbia Encyclopaedia 2. Neuss, Geoffrey (2007). Chemistry Course Companion. Oxford: Oxford University Press. 3. http://books.google.com.au/books?id=nkwM28diKF4Cpg=PT109lpg=PT109dq=deflection+charged+rodsource=blots=dk2TPy7IOfsig=g-MDZP6Q5kDsur57EIejpgJ54bghl=enei=48FrSp2bFIzusQOsy72WBQsa=Xoi=book_resultct=resultresnum=2 4. Department of Physics and Physical Science, University of Nebrasky, Kearney Falling Water http://rip.physics.unk.edu/CyberTextBook/fallingwater/ 5. http://books.google.com.au/books?id=nkwM28diKF4Cpg=PT109lpg=PT109dq=charged+rod+deflect+watersource=blots=dk2TQr4PPgsig=iwM-1qHxsAtaF9XoGZ1Mw9UCn6ghl=enei=OStsSqjFIo6qtgOT16WWBQsa=Xoi=book_resultct=resultresnum=3
Tuesday, January 21, 2020
Henrik Isbens A Dolls House :: A Dolls House Essays
Synopsis      The play begins on Christmas Eve. Nora Torvald enters the living room carrying packages. Torvald Helmer, her husband, enters. He says that she shouldn’t have spent so much on Christmas gifts. He says that they have to be careful with money for now, but that he got a promotion at the bank that will increase their quality of life.      Helene, their maid, says that Dr. Rank has come to visit. Also, Nora’s school friend, Kristine Linde, comes. The two have not seen each other in years. Nora tells Linde about her life. She says that Torvald had heath problems earlier in the marriage, and they had to go to Italy so he could recover.      Mrs. Linde tells Nora that her husband died, leaving her with no money and no children. She wants Torvald to get her a job. Nora says she will speak to Torvald, and tells her that she illegally borrowed the money to pay for the trip to Italy. For years, she worked and saved in secret to repay the debt. Soon it will be fully repaid.      Krogstad, an employee at the bank, and Dr. Rank arrive. Rank says that Krogstad is â€Å"morally sick†. Nora is unnerved by Krogstad’s presence. Torvald says that he can probably get Mrs. Linde a job at the bank. Rank, Torvald, and Linde depart. The children arrive with Anne-Marie, their nanny. Nora plays with the children until she notices Krogstad. He is revealed to be the source of the illegal loan.      He says that Torvald wants to fire him. He asks Nora to try to talk Torvald out of it. Krogstad says that he will tell about the loan if he gets fired. Nora tries to get Torvald not to fire him, but he says Krogstad is immoral.      On Christmas, Nora is nervous. Nora again begs Torvald not to fire Krogstad. He refuses. Torvald sends the maid to deliver Krogstad’s letter of dismissal.      Rank arrives and tells Nora he is dying. She flirts with him. He says he is in love with her.      Krogstad demands an explanation for his being fired. He tells Nora that she must get him rehired to a higher position. He puts a letter in Torvald’s letterbox detailing the illegal loan. (Nora forged her father’s signature to get it.) Nora tells Mrs. Linde everything. Mrs. Linde says to distract Torvald from the letterbox until she talks to Krogstad.      Krogstad and Mrs. Henrik Isben's A Doll's House :: A Doll's House Essays Synopsis      The play begins on Christmas Eve. Nora Torvald enters the living room carrying packages. Torvald Helmer, her husband, enters. He says that she shouldn’t have spent so much on Christmas gifts. He says that they have to be careful with money for now, but that he got a promotion at the bank that will increase their quality of life.      Helene, their maid, says that Dr. Rank has come to visit. Also, Nora’s school friend, Kristine Linde, comes. The two have not seen each other in years. Nora tells Linde about her life. She says that Torvald had heath problems earlier in the marriage, and they had to go to Italy so he could recover.      Mrs. Linde tells Nora that her husband died, leaving her with no money and no children. She wants Torvald to get her a job. Nora says she will speak to Torvald, and tells her that she illegally borrowed the money to pay for the trip to Italy. For years, she worked and saved in secret to repay the debt. Soon it will be fully repaid.      Krogstad, an employee at the bank, and Dr. Rank arrive. Rank says that Krogstad is â€Å"morally sick†. Nora is unnerved by Krogstad’s presence. Torvald says that he can probably get Mrs. Linde a job at the bank. Rank, Torvald, and Linde depart. The children arrive with Anne-Marie, their nanny. Nora plays with the children until she notices Krogstad. He is revealed to be the source of the illegal loan.      He says that Torvald wants to fire him. He asks Nora to try to talk Torvald out of it. Krogstad says that he will tell about the loan if he gets fired. Nora tries to get Torvald not to fire him, but he says Krogstad is immoral.      On Christmas, Nora is nervous. Nora again begs Torvald not to fire Krogstad. He refuses. Torvald sends the maid to deliver Krogstad’s letter of dismissal.      Rank arrives and tells Nora he is dying. She flirts with him. He says he is in love with her.      Krogstad demands an explanation for his being fired. He tells Nora that she must get him rehired to a higher position. He puts a letter in Torvald’s letterbox detailing the illegal loan. (Nora forged her father’s signature to get it.) Nora tells Mrs. Linde everything. Mrs. Linde says to distract Torvald from the letterbox until she talks to Krogstad.      Krogstad and Mrs.
Sunday, January 12, 2020
Determination Lesson Essay
The greatest lesson I have learned in my life thus far. I have found this to be true in most aspects of my life, for all of my growth and success has come as a result of determination and perseverance. No matter how desperate the situation may be, no matter how badly it seems I will succeed. While I had experience failures and hardships, this experience taught me the most valuable lessons, making me a stronger person and building the character which drives the individual I am today. I was raised in a small household and participated in many different things growing up. Since I was young, I have striven to achieve my goals; I call it a â€Å"determination to succeed.†Without a â€Å"determination to succeed,†giving up in life, when a situation seems impossible to overcome, becomes second nature. The methods one uses to overcome the challenges faced in life affects how one acquires success. For example, my ancestors did not overcome their struggle for equality without s elf-determination to better their lives. Thus, their lives have been an inspiration for me. The motivation to excel, though sometimes forgotten in my generation, is a quality that needs nourishment. My parents taught me that it takes hard work and to be successful. They pushed me to follow my dreams from a young age child which has carried over into my adulthood. Their guidance and belief in me gave me the strength to believe in myself, which I consider to be main reason I have experienced so much success in my life so far. I learned to go back to school to get my degree. Learning is a never-ending road, and I truly believe that I must continue to learn in order to improve and excel in my career, as well in all other areas of life. During my first year at Wayne County Community College I developed a passion for the field of associates of arts and associates of general study’s degree. I enjoyed learning about all my classes, but found that analyzing the two degrees that I’m within the school to ensure efficient operation is very exciting and motivating for me. Although the opportunity was present, I knew it would take hard work and a great deal of learning to understand how to be successful. The experience my desire to learn and motivations to succeed are constantly growing stronger. I want to take this characteristics into my graduate studies, so that I may continue to develop on a different level. I believe the knowledge and experience I will receive with an associate’s degree will give me the expertise I need to excel in my future career. My greatest achievements in life is undoubtedly my greatest failures in life. To learn from my mistakes which I have lived all my life and will continue to live by. All my life all other humans have made mistake. However unlike others, I have squeezed through these huge walls of mistakes and have come out as reformed individual, with a positive outlook on life. They say that experience is the best teacher and what better way to get experience than from my own mistakes. May it be in terms of academic, self-reform or even in helping others, I have made mistakes? But I have never let them overpower my confidence and perseverance to succeed in life. It is rightfully said that mistakes are the stepping stone for success. In my past, I have countless mistakes, and thus I assume that I am on the right path. The desire to do off beaten-path things takes away my fear of failure and lets me take risks without thinking about the outcome. I have always tried to remain consistent throughout my en tire academic life, but to err is human, and that I am. By this I mean to say that like others
Saturday, January 4, 2020
Subscribe to:
Posts (Atom)