Discussion and Scientific Explanation
Our first goal in Project 7 was to determine what our three unknown solutions were. We did this through a series of tests. Our first test was a series of anion tests. We performed anion tests to determine whether any of the following anions were present in our solution: chloride, sulfate, nitrate, carbonate, and acetate. Our first solution, labeled as B, had only the chloride test come out positive. The next solution, C, tested positive for acetate, as did our last solution, E. We next performed anion tests. These included flame test, as well as an ammonium test. For the flame test, certain cations turn flames different colors, so we used this knowledge to test to see which cations could be present in our solutions. During this test, the only solution that appeared to turn the flame any color was solution C, which turned the flame bright orange, indicating the sodium ion was present. This led us to the conclusion that solution C was sodium acetate. We next performed an ammonium test, which involved mixing our solutions with sodium hydroxide, and smelling the resulting solution in order to detect an ammonia smell. Solution B was identified as smelling like ammonia, indicating the presence of the ammonium cation. From this, we identified solution B as ammonium chloride. We next checked the pH of all three of the solutions, first by using litmus paper. Solution C was slightly basic, solution E and B were both acidic, with a pH around 4. Since we knew that solution E had acetate, and was acidic, and did not turn the flame any color, we determined it was acetic acid, as none of the ions in acetic acid would turn a flame any color.
Once we identified our substances, we began our titrations. This ...
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...for the original titration, shown in Table 5. This could be due to perhaps usage of the wrong indicator, or of not stopping the titration exactly when the color changed.
The next week was dedicated to the titration of household supplies. For this, we used two sodas, Cheerwine, and Diet Coke, as well as dish soap. Dish soap, along with many other household cleaning agents, has buffering properties. A buffer acts as a pH stabilizer. It is a combination of a weak acid and its conjugate base, or a weak base combined with its conjugate acid. If a strong acid ion is added, the buffer simply replaces it with a weak acid ion, therefore causing little change in the pH of the solution. Household cleaning products usually have some form of a buffer, because otherwise, they would burn skin to touch. As expected, the two sodas were originally acidic, while the soap was basic.
The purpose of the Unknown White Compound Lab was to identify the unknown compound by performing several experiments. Conducting a solubility test, flame test, pH paper test, ion test, pH probe test, conductivity probe test, and synthesizing the compound will accurately identified the unknown compound. In order to narrow down the possible compounds, the solubility test was used to determine that the compound was soluble in water. Next, the flame test was used to compare the unknown compound to other known compounds such as potassium chloride, sodium chloride, and calcium carbonate. The flame test concluded that the cation in the unknown compound was potassium. Following, pH paper was used to determine the compound to be neutral and slightly
The primary goal of this laboratory project was to identify an unknown compound and determine its chemical and physical properties. First the appearance, odor, solubility, and conductivity of the compound were observed and measured so that they could be compared to those of known compounds. Then the cation present in the compound was identified using the flame test. The identity of the anion present in the compound was deduced through a series of chemical tests (Cooper, 2009).
A test tube containing 0.2 gram of manganese dioxide was weighed. After recording the data, 1 gram of the unknown substance was then added into the test tube and weighed again, the data recorded also. The test tube was heated using a gas burner and was held by the clamps of the iron stand. The heating continued until there was no more gas rising out of the mouth of the tube which signified that the chemical reaction had already ceased. The test tube was set aside, allowing it to cool to room temperature. When it had reached room temperature, it was weighed and the data recorded. After recording the weight of the test tube and its contents after heating, a second test tube was also weighed with 0.2 gram of manganese dioxide in it. The data was then recorded. A second unknown which is a mixture of potassium chlorate and potassium chloride weighing 2 grams was then placed on the test tube, it was weighed and the data recorded as well. It was held by the clamps on the iron stand and heated using the gas burner. Similar with the first part of the experiment, it was heated until there was no more gas ascending out of the test tube. It was allowed to reach room temperature. The test tube was the weighed and data recorded.
Refer to Chemistry Lab # 2 – Investigating Changes. No changes have been made in this experiment. Methods = == ==
In my team’s investigation, we were trying to figure out four unknown powders based on the known powders we had. Our research question was, how do different chemicals change the color of the flame. First in the experiment, we prepared our lab space by making sure we had a clear countertop and had a beaker full of water ready for the hot splint to be dumped into. We all put our hair back and put our goggles on and then proceeded to turn the Bunsen burner on. After we put the Bunsen burner on, Mr. Young adjusted our flame and we sent someone to grab the first chemical to burn. We burnt chemicals on the wooden splint one after one observing the color the flame produced, recording the color, and proceeded to put the splint in the water afterwards.
One possible source of experimental error could be not having a solid measurement of magnesium hydroxide nor citric acid. This is because we were told to measure out between 5.6g-5.8g for magnesium hydroxide and 14g-21g for citric acid. If accuracy measures how closely a measured value is to the accepted value and or true value, then accuracy may not have been an aspect that was achieved in this lab. Therefore, not having a solid precise measurement and accurate measurement was another source of experimental error.
Some examples of acids include coffee, soda, orange juice, and lemon juice. When used in cleaning products, acids help break down stains like rust or mineral deposits. "Acids clean by attacking, dissolving, and breaking down the stains making them easier to remove." ("High pH = Basic (alkaline)") Bases, substances that have a PH level higher than 7, are usually bitter and are sometimes called alkalines. Basic solutions are used to remove fatty and oily soils from surfaces. "Basic solutions attack fatty and oily soils, breaking them into component parts that are easier to remove from surfaces or fabrics." ("High pH = Basic (alkaline)") One example of cleaning with bases is when you clean your hands with soap. Other basic solutions are used to clean and disinfect surfaces in your home such as bleach or all purpose
The materials used during Part 2 of the experiment includes an unknown metal (either A, B, or E), an analytical balance 200 mL of tap water, a 400 mL beaker, a hot plate, 50.0 mL of cold water, and a calorimeter. The materials used during Part 3 of the experiment includes 50.0 mL of deionized water, 2 g of NH4Cl, an analytical balance and a
However, in order to measure the rates of reaction, sodium thiosulphate and starch are added. Sodium thiosulphate is added to react with a certain amount of iodine as it is made. Without the thiosulphate, the solution would turn blue/black immediately, due to the iodine and starch. The thiosulphate ions allow the rate of reaction to be determined by delaying the reaction so that it is practical to measure the time it takes for the iodine to react with the thiosulphate. After the all the thiosulphate has reacted with the iodine, the free iodine displays a dark blue/black colour with the starch. If t is the time for the blue/black colour to appear, then 1/t is a measure of the initial rate.
Chemistry: Acid-Base Titration. Purpose: The objective of this experiment were: a) to review the concept of simple acid-base reactions; b) to review the stoichiometric calculations involved in chemical reactions; c) to review the basic lab procedure of titration and introduce the student to the concept of a primary standard and the process of standardization; d) to review the calculations involving chemical solutions; e) to help the student improve his/her lab technique Theory: Titration was used to study acid-base neutralization reaction quantitatively. In acid-base titration experiment, a solution of accurately KHP concentration was added gradually to another solution of NaOH concentration until the chemical reaction between the two solutions was completed. The equivalence point was the point at which the acid was completely reacted with or neutralized by the base.
CHEMTUTOR ACIDS AND BASES. (n.d.). CHEMTUTOR ACIDS AND BASES. Retrieved February 16, 2014, from http://www.chemtutor.com/acid.htm
The pH of the common household substances did have a few recognisable patterns. Almost all of the substances ranged from pH levels of 4-8, with only 2 with high acid levels. We tested lemon juice which had a pH level of 2, making it a strong acid. I expect that most other food items would have a higher pH level to avoid damage to the mouth and throat during/after consumption. Lemon juice contains citric and ascorbic acid (vitamin c)
For this assignment I have chosen to demonstrate my knowledge about Aconite. In muggle society Aconite is also known as ‘The Queen of poisons’, Blue rocket, Devil’s helmet, leopard’s bane and women’s bane. In magic society Aconite is known as Monkshood or Wolfsbane. Aconite is a plant with magical and non-magical properties. Aconite has dark green leaves. The stem is crowned by large blue, purple, white, yellow or pink flowers. These herbaceous perennial plants grow in the wild, in forest and in mountain ranges of moderate temperatures. .
Anion gap is the difference of anion level and cation level within organism body fluid. The common cation that being measured are sodium ion and potassium ion, but potassium ion usually not included within the calculation due to very low amount within human body fluid (Emmett and Narins, 1977, pp. 38). The common anions used in the calculation of anion gap are chloride ion and bicarbonate ion. The calculation of anion gap as following:
For centuries, many scientists and researchers have pondered on the idea of combining two or more substances together to create something new. These explorations have led to the idea of what kind of reactions would occur when diverse elements are combined. This is a concept known as chemistry, a part of science that corresponds with how matter is created from different properties and the process it goes through to create a new substance. Chemistry is a scientific concept that is used in everyday life and is a crucial part in the development of new technology and substances that allow today’s quality of life. The use of chemistry branches off into many different routes, including medical related fields, agriculture, and even in weapons of