Andrea Bouchan* Meredith TA: Felicia Konopka September 20, 2015 Results and Discussion The purpose of this experiment was to use qualitative analysis methods to identify the metal nitrate salts that were present in an unknown solution for parts A and B. In part C, a third method, the cation flame tests, was used to identify cation solutions based on the color that was emitted by the flame. In parts A and B, the results were the presence of the lead cation and the barium cation. Lead was identified in part a during step six when the solution turned cloudy and very yellow, indicating the presence of a lead precipitate. During part B, step 13, the solution turned foggy and yellow then settled into a white precipitate, indicating the presence of barium. These results were reasonable. The unknown solution was number 4. During part C, the BaCl2 solution emitted a yellow color when it was placed into the bunsen burner flame. KCl was lavender, NaCl was orange, CaCl2 was also orange, LiCl was magenta, and CuCl2 was green. These results were also expected and coincide well with the given cation flame color table. …show more content…
It was necessary to add HCl to the given unknown solution at the beginning of the experiment because it turned the solution into PbCl2 and AgCl by providing Cl anions for either the Pb or Ag cation to bond to.
This made it easier to separate the given cation from the rest of the solution because cations have a positive charge and are inherently attracted to an anion’s negative charge. During step 5, the sample was heated because it acts as a catalyst that forces the molecules to move faster, fostering a chemical reaction. K2CrO4 was added in step 12 because the CrO4 is negatively charged and would bond either with the Ba cation or with the Ca cation. In step 12, the possible false positive refers to the solution seeming to have the barium cation because the solution was not fully dissolved and could resemble one that has a
precipitate. Lead formula unit equation: Pb^2+(aq) + K2CrO4 (aq) —> PbCrO4 (s) + 2K^+ (aq) Lead total ionic equation: Pb^2+ (aq) + 2K^+ (aq) + CrO4^2+ (aq) —> PbCrO4 (s) + 2K^+ (aq) Lead net ionic equation: Pb^2+ (aq) + CrO4^2+ (aq) —> PbCrO4 (s) Barium formula unit equation: Ba^2+ (aq) + H2SO4 (aq) —> BaSO4 (s) + H2 (g) Barium total ionic equation: Ba^2+ (aq) + H2 (aq) + SO4^2- (aq) —> Ba^2+ (s) + SO4^2- (s) + H2 (g) Barium net ionic equation: Ba^2+ (aq) + SO4^2- (aq) —> BaSO4 (s) A centrifuge was used to separate the precipitates from their solutions because it forces heavier things down to the bottom. The centrifuge was balanced by making sure that the tube placement was symmetrical and that the tubes had similar mass. If the centrifuge was not balanced it could have been damaged. Flame tests were used to identify cations in a solution because anions did not produce a certain color during a flame test and the cation produced its color regardless of the anion it was bonded to.2 A limitation that the flame test had was that a lot of cations produce very similar flame colors.1 References Frenzel, Wolfgang. "Simultaneous Ion Chromatographic Determination of Anions and Cations by Series Conductivity and Flame Photometric Detection." Analytica Chimica Acta 277.1 (1993): 103-11. Print. Frenzel, Wolfgang. "Simultaneous Ion Chromatographic Determination of Anions and Cations by Series Conductivity and Flame Photometric Detection." Analytica Chimica Acta 277.1 (1993): 103-11. Print.
Solid A was identified to be sodium chloride, solid B was identified to be sucrose, and Solid C was identified to be corn starch. Within the Information Chart – Mystery White Solid Lab there are results that distinguishes itself from the other 4 experimental results within each test. Such as: the high conductivity and high melting point of sodium chloride, and the iodine reaction of corn starch. Solid A is an ionic compound due to its high melting point and high electrical conductivity (7), within the Information Chart – Mystery White Solid Lab there is only one ionic compound which is sodium chloride, with the test results of Solid A, it can be concluded that is a sodium chloride. Solid B was identified as sucrose due to its low electrical
The purpose for this lab was to use aluminum from a soda can to form a chemical compound known as hydrated potassium aluminum sulfate. In the lab aluminum waste were dissolved in KOH or potassium sulfide to form a complex alum. The solution was then filtered through gravity filtration to remove any solid material. 25 mLs of sulfuric acid was then added while gently boiling the solution resulting in crystals forming after cooling in an ice bath. The product was then collected and filter through vacuum filtration. Lastly, crystals were collected and weighed on a scale.
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
During our investigation we first decided how much sodium bicarbonate we would be using. We decided on 11 grams which was about half of the crucible. We then used the bunsen burner to heat up the sodium bicarbonate. We heated the sodium bicarbonate expecting there to would be a chemical reaction and the atoms would be rearranged during thermal decomposition. We heated the sodium
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).
...form 〖PbCrO〗_4 and then process it through a filter. After filtering the 〖PbCrO〗_4 I had to dry the 〖PbCrO〗_4 residue in the drying oven for 30 minutes at 80℃. Then let it cool for 5 minutes and weigh it and finally make a few calculations to obtain the theoretical, actual, and percent yields of 〖PbCrO〗_4. I was able to fulfill the experiment because I obtained all the answers to the equations in an accurate amount. I believe this experiment was a success due to my hypothesis of, If physical methods are used to separate 〖 PbCrO〗_4 precipitate from the reaction mixture then I can successfully calculate the theoretical, actual, and percent yields, being correct.
The purpose of conducting experiment was to determine the identity of white compound. Based on the 5 gram of unknown white compound several experiment conducted including solubility test, pH test, flame test, and ion test. Several materials including chemicals used throughout experiment and will be described through paragraphs.
The Armenian genocide ruins Vahan Kenderian’s picture-perfect life. Vahan is the son of the richest Armenian in Turkey and before the war begins, he always has food in his belly and a roof over his head in the book Forgotten Fire by Adam Bagdasarian. Life is absolutely quintessential for Vahan, until the war starts in 1915, when he endures many deaths of his family, losses of his friends, and frightening experiences in a short amount of time. He is a prisoner of war early in the book and is starved for days. As he goes through life, he is very unlucky and experiences other deaths, not just the deaths of his family. Vahan ultimately becomes the man his family would want him to be.
As a result, the laboratory experiment was determined to be successful and the two product samples obtained and completed calculations displayed that overall bromide was a stronger nucleophile as the chloride ion was more electronegative than bromide, which allowed it to hold electrons in closerE. In conclusion, since bromide is less electronegative and has more electrons, it was able to share the unpaired electrons more easily than chlorideA. These results were expected, as the alkyl bromide would be the major product of procedure A as it followed the SN2 mechanism which was based on nucleophile strength and the product from procedure B would be a near-equal mixture as it followed the SN1 reaction mechanismC. The methods used during this experiment allowed for a successful completion and determination of the better nucleophile, but other additions and observations would have been interesting and beneficial as well. A possible examination of the two sample products collected using pH tested values or observation of sample spotted chromatography paper under a
Catching Fire: How Coooking Made us Human by Richard Wrangham is a fresh perspective on the evolution of humankind. Wrangham has made a concentrated effort to prove that humans have evolved particular adaptations, like bipedalism, due to the introduction of cooked foods into their diet. In his book, he is legitimately arguing that humans are the way they are because early on in human evolution, early man discovered fire, discovered the joys of cooked foods, and developed all sorts of fascinating traits still being utilized today.
This smoke bomb lab helped me understand chemical bonding and reactions by starting from the very beginning with mixing the nitrate, sugar, and melted crayon. Mixing them formed a texture almost like powdery peanut butter with some liquid which was actually pretty interesting. The second chemical bonding I seen was that, once putting the solution in the tin-can and it started solidifying due to all the stuff we mixed together. It didn’t take long at all for it to start forming into a solid. When we went outside and lit the wick on fire showed the main chemical reaction throughout the whole experiment. The nitrate reacting with the lighted wick started a big fire in one of the groups cans but some of the other groups bombs didn’t get to light like it was supposed to and the wick just burned out. I was one of the groups whose bombs didn’t work properly. I think it’s because we didn’t put the wick in deep enough to our solution so when we lit it the fire just burned out before going into the solution.
In “Barn Burning” the setting is a time when people drove horse wagons and the workingmen were generally farmers. The major character in this story is Colonel Sartoris Snopes, called “Sarty” by his family who is a ten-year-old boy. In the beginning, Sarty is portrayed as a confused and frightened young boy. He is in despair over the burden of doing the right thing or sticking by his family, as his father states,” You got to learn to stick to your own blood or you ain’t going to have any blood to stick to you.”
The porpoise of these is to determine the Specific Heat. Also known as Heat Capacity, the specific heat is the amount of the Heat Per Unit mass required to raise the temperature by one degree Celsius. The relationship between heat and temperature changed is usually expected in the form shown. The relationship does not apply if a phase change is encountered because the heat added or removed during a phase change does not change the temperature.
Chemistry Proposal: Bomb Calorimeter Introduction: A calorimeter is an object used to measure the heat of chemical reactions. The calorimeter is very accurate because it prevents heat loss. There are many types of calorimeters such as Simple calorimeter which consist of thermometer attached to a container (cup or plastic container), or Bomb calorimeter which is a more advanced and can measure under higher temperature.
The electrons then emit a photon of light. The light for the corresponding wavelength is determined by specific energy level of the certain element, resulting in different colors to appear. Due to sodium’s photons, a yellow and orange light is projected. For the chloride anion tests, the silver salts found in the unknown compound were insoluble, because a mixture between sulfate and silver is insoluble according to the solubility rules; therefore, when mixed with nitric acid and with silver nitrate, a precipitate was formed. The anion would only be chloride if the other four tests proved to be negative. The sulfate anion test also proved positive, as a white precipitant was formed when the unknown substance was mixed with barium chloride and hydrogen chloride; the mixture between barium and sulfate is also insoluble according to the solubility rules. For the acetate, nitrate, and carbonate tests, the results came out negative because there was no definite chemical reaction with the