ELECTROCHEMICAL CELLS Purpose: In this experiment, several different half-cells will be prepared and connected to find the voltages generated. Also, the concentration will be change in one of the solutions to see how this affects the cell potential. Thirdly, the electrical potential of a cell containing silver and silver chloride will be measured. Lastly, a cell containing copper (II) and ammonia will be constructed. The potential and the Nernst equation will be used to calculate the formation constant of the tetraamminecopper (II) complex ion. This experiment uses a microscale technique. Procedure: 1. Collect materials and put on goggles for eye protection. 2. Prepare a test cell to measure the voltage of the copper and zinc half-cells. 3. Put approximately 2 mL 1.0 M zinc nitrate solution in one of the center wells of a 24-well plate. 4. Put approximately 2 mL of 1.0 M copper (II) nitrate in an adjacent well. Polish small strips of zinc and copper metal, and place the metal in the appropriate well containing the solution of the ions of that metal. 5. Take a small strip of filter paper that has been soaked in potassium nitration solution, and drape it across the wells so that one end dips in the solution in each well. This will act as a salt bridge. 6. Use a voltmeter to measure the potential difference between the two half-cells. 7. Connect the meter so the voltage reading is positive. 8. Use the most sensitive scale which is practical. Make note as to which electrode is the anode and which is the cathode. 9. When the voltmeter reads a positive voltage, the electrode connected to the positive terminal is the cathode and is undergoing reduction. The oxidation is occurring at the electrode connected to the negative terminal, the anode. 10. Prepare half-cells in other wells of the 24-well plates. 11. First make a diagram of the order of the solutions in the wells so the different solutions will not be confused. 12. Pour some 1.0 M solution of each of the ions into different wells. 13. Polish the metals with sandpaper or steel wool so that they are shiny, and insert them into the wells which contains the ion of the same metal. 14. Use fresh strips of filter paper soaked in 1.0 M potassium nitrate as salt bridges. 15. The zinc electrode will be designated as the standard electrode. Measure the potential difference between the zinc electrode and each of the other electrodes. 16. Record the data. 17. Measure the potential difference between at least six combinations of the various electrodes. 18. Use table of electrode potentials to predict the voltage and which half-cell will be the anode and which the cathode.
Therefore any changes in the cell are ascribable to the working electrode. The control of potential of working electrode with respect to reference electrode is equivalent of the controlling of energy of electrons within the working electrode. As shown in Fig. 1.3, scanning the potential in the negative direction makes the electrode a stronger reductant, whereas scanning the potential in the positive direction makes it a better
One of the key questions raised by Rupert Sheldrake in the Seven Experiments That Could Change the World, is are we more than the ghost in the machine? It is perfectly acceptable to Sheldrake that humans are more than their brain, and because of this, and in actual reality “the mind is indeed extended beyond the brain, as most people throughout most of human history have believed.” (Sheldrake, Seven Experiments 104)
The letter Christopher Columbus wrote back to Spain to report his findings in the New World sparked intrigued me and sparked my imagination. Why I have been so absorbed in this letter I can not explain. This letter is supposed to be about describing an unknown land, a land that has not been seen by anyone besides the natives, but it seems that there is more to it than that. Columbus is known in elementary schools as the man who found the New World, and is regarded as a hero. To the contrary, historians who have done more research on Columbus say that he was driven by fame and fortune and that he was tyrannical in his ways with the indigenous peoples of the places that he came to find. I feel that the contradictory tones Columbus uses gives this letter an eerie feel, and Columbus’s eventual desire to take over the indigenous peoples brings doubt on his reliability as an accurate and fair eyewitness.
On a daily basis, a majority of people across the world consumes meat products in their diet, yet a small percent of people have chosen the unique lifestyle of being a vegetarian. Although everyone has to make their decision on whether to follow a meat based or vegetarian based diet, there have been continuous debates on the benefits that come from being a vegetarian versus eating meat. According to nutritionists, it was concluded that eating a more vegetarian based diet has greater positive values to the health of the body than consuming meat. The benefits of a vegetarian diet over the meat diet are determined by the nutrients that an individual may gain from being a vegetarian. There are numerous organizations and societies that continually educate people about the best ways of living a healthy lifestyle. The main objective of this paper is to assess the importance of the vegetarian diet compared to the meat based diet.
In a 100ml beaker place 50mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved.
Another widely used primary cell is the zinc-mercuric-oxide cell, more commonly called a mercury battery. It can be made in the shape of a small flat disk and is used in this form in hearing aids, and electric wristwatches. The negative electrode consists of zinc, the positive electrode is of mercuric oxide, and the electrolyte is a solution of potassium hydroxide. The mercury battery produces about 1.34 volts.
8.) Balance – I chose this, as it is very precise (it measure to 2
“Why the Rich are getting Richer and the Poor, Poorer” written by Robert Reich, describes as the title says, why the rich are getting richer and the poor, poorer. In Reich’s essay he delves into numerous reasons and gives examples of each. It makes one wonder if the world will continue on the path of complete economic separation between the rich and the poor.
However, some of the people in the country wanted to go on with their life freely by being a part of a welfare, and some of them strived and worked hard to get job without bothering which class they belong. Furthermore, distribution of wealth is a huge demand of every citizen of America. Everyone nowadays are trying to look down for every lower class as they did not give any benefit for the country, that they are just there living waiting for the benefits they will receive from the government. That benefit comes from the middle class that is trying to level with what the higher class can have and give a positive reputation for the country’s economy. Because money is seen as the very important thing today to survive and to do anything. On the other side, some people in America, mostly for those who are in the lower class have gone through a financial crisis due to overspending, insufficient fund or pay from their work to support himself/herself and/or his/her family.
== § Test tubes X 11 § 0.10 molar dm -3 Copper (II) Sulphate solution § distilled water § egg albumen from 3 eggs. § Syringe X 12 § colorimeter § tripod § 100ml beaker § Bunsen burner § test tube holder § safety glasses § gloves § test tube pen § test tube method = == = =
Growing up in India, I have heard much about vegan diets. Many people take on vegetarian diets due to religious beliefs, personal interest, ethical issues, and many other reasons. So what exactly is a vegetarian diet? Is it better for the body? Vegetarian diets can provide the necessary nutrients; as well, as reduce the likelihood of chronic diseases caused by unhealthful diet; however, if the food intake is not closely monitored it can lead to deficiencies. Then the question becomes, if vegetarian diets are better, then why exactly do we need meat products in our diet? In this research paper, I want explore the pro and cons of vegetarian diet and its implications.
We are all boats it just depends on the type of boat and how well it is built. That is the structure of Reich’s essay he uses a lot of metaphors to get across what is really happening in the United States. He says we all used to be in the same boat now we are in different boats some are sinking some are about to sink and the other boats are doing just fine and looking for an upgrade. “It’s a game that gets people in the lower and middle classes comfortable with a declining standard of living, provided they can be made to believe some rich guy somewhere is suffering worse than they are.” (Hayward) Having money is like a game you are not rich or poor it is the way you think about your life. If you are happy it should not matter how much money
A Critical Opinion by Robert B. Reich on Why The Rich Are Getting Richer and the Poor, Poorer
To investigate the temperature change in a displacement reaction between Copper Sulphate Solution and Zinc Powder
I have been through so many things in my life and I have made many bad decisions. The best thing with making wrong decisions are learning from them. One of the worst decisions in my life was dropping out of college when I was younger. One day I’m hoping to show people no matter how old your are or what your have been through, you can still go back to school and help people but it first starts with yourself. Deciding to go back to school was hard, but I wanted to make a difference in someone’s life.