Crime and Dye Lab Essay

Light is usually viewed as a depart of the heating of a spunk. The mettlesomeer the temperature at which the substance is heated, the greater the vibrations that hold in to certain take down intensity given off by the molecule. It is this alike theory that suggests why steel g firsts red hot when heated to high enough temperatures. The process of light emissions can also be induces with with(predicate) other sum.1One of such means termed fluorescence occurs when a substance can be induced into giving off light is through absorption of a photon through light or other means of radiations. During this process, negatrons are excited from their standard state. The electrons jump from their highest unoccupied orbital (HUMO) into a certain level of the unoccupied orbital (LUMO). As the electrons loose energy, they perish back to a lower orbital, thus emitting light.1, 2During the process stellar(a) to fluorescence, a certain change could occur during the excitation of the electr on, changing the device of the electron as it gets excited. This change has to be undone as the electron goes back to its standard state. The emitting of light in this process is known as phosphorescence. The process of fluorescence is much faster than phosphorescence. This is due to the fact that in phosphorescence, the electron has to undergo an extra step of undoing its current spin. This process is thermodynamically unfavorable compared to fluorescence.1, 2The last means by which light could be generated is through chemiluminescence. In such a case a chemical reaction occurs, ca using an excitation of the reaping. As this product decays into its standard state, light is emitted. This form of luminescent is different from the previous two in the sensation that no absorption of light is required to induce the glow. The glow results from the product of the chemical reaction having to be in an exited state or of high energy. 1The process of photon absorption and emission is cer tain a phenomenon that plays a vital role in our society. Such importance is expressed during redeem operations, where victims can be easily found due to waving of a fluorescent material at night. It is evident that fluorescence becomes heavy when a thermally induced light emission is deemed impossible.1, 2Separation techniques were concepts that were important in the course of this experiment. One of such is through the means of UV Vis Spectrophotometer. The constituents of sign dyes can be determined using a spectrophotometer. By placing the dyes in the spec, motley wavelength peaks will be obtained. These peaks can be used to check out the constituent pretensions making up the dye.Another important form of separation used during this experiment is chromatography. Chromatography utilizes the differences in polarity of substances as means of separation. Such is the case of a crime lab involving the finding of a compile used in writing on a piece of paper. If a pen out of fo ur is used to write a note, the particular pen can be observeed using chromatography. The dyes of all four signs and the unknown ink can be obtained. This ink can be run through a chromatograph column, allowing a result to run above the ink dyes, carrying them along.After a certain express the RF taxs of all the inks can be used to detect the particular ink. The RF value is the distance the ink travels divided by the distance travelled by the solvent. The ink with the same RF value as the unknown is the same ink used. Chromatography has a wide pasture of use. It use can be stretched from this as it can also be used to indicate the component amino acids found in various proteins. The protein can be run through the column, resulting in the various amino acids that make the protein, to be separated.1, 2Materials and Methods (Summarized from Lab Manual) 1Procedure* Phosphorescence ii different polyaromatic acids, 1- naphthoic acid and 4-biphenylcarboxylic acid, were obtained and drops were added unto two filter paper. The solvents heated to dryness for 11 minutes using a hot coat on low heat. The filter papers were wherefore rigid under long and sententious wavelength ultraviolet lamps. Observation of the intensity and era of glow were recorded.* FluorescenceTonic peeing was poured into a beaker. Long and short wavelength UV lamp was shined above the beaker. Observations were recorded. Now, a beaker of irrigate was taking to the UV lamp and was shined at the beaker. Observations were recorded. After, 3 drops of concentrated fluorescein resolving power was added into the beaker. The UV lamp was shined above the beaker and observations were recorded.* Chemiluminescence2 mL of Tekrakis-(dimethylaminoethylene) was added into a small stress render. This test tube was taken to the UV lamp and shined at. Observations about the intensity and duration of glow were recorded.After, 1 mL of luminol in DMSO was added into volt test tubes. Now, in from dist ributively one test tube fluorescein, rhodamine, rubrene and perylene resolutenesss were added in 4 four of the five test tubes. Observation of the color of distributively solution was recorded. At this point, 1M NaOH was added into each test tube and was thus shined with a UV lamp. Further observations were recorded. ultimately 1 g of Al2O3 was added into four 250 mL Erlenmeyer flask. This was mixed with 1 mL of 3% H2O2. In each flask, perylene, tetracene (2,3-benanthracene), 9,10-Dipehenylanthracene, and rubrene were added respectively. Now, 1 mL of oxalic chloride was added in each flask and swirled. Observations were then recorded.* Crime LabA water toilet was heated and maintained at 650C. Now, scribbles were made on papers from each of the four pens. The paper with each scribble was cut into small pieces and placed into a marked test tube. Also, a scribble of an unknown pen was obtained. The paper was also cut into small pieces and placed in a test tube. 2 mL of methanol w as added into each test tube and was placed in the hot bath for 5 minutes. The test tubes were allowed to cool, the color of the inks were recorded and poured into five cuvettes. Using a UV-Vis spectrophotometer, the wavelength peaks and absorbance of each ink solution were recorded.Four of the five dyes were then poured into new marked test tubes. The solutions were then boiled for 14 minutes until the there were less than 1 mL. The solutions were allowed to cool. Now, a 250 mL beaker was obtained. In it was added a small amount of methanol (less than fractional a centimeter in superlative). A filter paper was then obtained and cut towards the end (B.1). This was placed at the side of the beaker. Finally, an alumna plate was cut in the dimension of 8 x 4 cm. A line was drawn at a 1 cm eyeshade using a pencil. In this line, drops of the four inks were spotted. This plate was then leaned inside(a) the end of the beaker (B.2). The plate was left in the solvent until it reached of the way up. The height the inks and solvent reached up the plate was recorded.