Thursday, August 14, 2014

Paper Chromotography

Dear Dad,
I know how interested you are in Chemistry, and I'd like to tell you about my most recent experiment today in my Chemistry class. As you know, Dad, a proper experiment should follow scientific method, and today's experiment was no different. Much of our background was knowledge previously learned in science class. Our teacher, Mrs. Gardner, asked a question and formulated the hypothesis for us, We just listened, sat down and followed the instructions. We created cards made from filter paper, which served as our stationary solvent, to separate our different solutes. We also prepared three different solutions, to dissolve the various pigments found in common marker dyes.  We tested seven different markers, both colors and makers of markers.  We used a blue, orange, yellow, brown, black, red and green markers from two different companies, and similarly used seven different FDC dyes (these are the primary dyes used by marker companies to produce their markers by mixing these FDC dyes).  The FDC dye colors used were blue 1, blue 2, red 3, red 4, green 3, yellow 5, and yellow 6.  We spotted a total of nine paper cards with each color; three cards each with the two different markers, and three of the FDC dyes with all seven dyes from each marker. We used three different solvents; a sodium chloride solution, isopropyl alcohol, and a Chromatography solution, which were our mobile solvents, and our stationary solvent was the paper. The three different sets of solutes which were the dyes; Crazy Art Markers, Vis-à-vis Markers, and FDC dyes.  The markers were comprised of dye solutions and were put together physically, which was evident in the separation of colors on our paper matrixes. The dyes each traveled differently depending on which solvent was employed.  The chromatography solution was a nonpolar solvent. Since our pigment molecules are polar, there were unable to dissolve in the solvent. This is evident by our data of the chromatography set. None of the pigments were dispersal with this solution. The alcohol, was very slow.  The alcohol molecule has both polar and non-polar parts, but mainly a non-polar solution. The NaCl solution being polar, dissolved the pigment molecules the best, and was able to quickly diffuse up the filter paper.   Since the NaCl solution spread the pigments the fastest, we noticed the most blurring.  The pigment molecules were more muddled because they spread so quickly.  Since the alcohol spread the pigments more slowly, the pigments had time to stratify more completely, giving us the vivid strata of different colors in each pigment blend. In this case, the heavier pigments were able to separate from the smaller ones, and clearly visible bands of color were evident. The attraction to the solvent is because of the polarity. Like dissolves like. The quantitative data (Rf) for the Crazy Art with sodium chloride were calculated below;
       6cm/6.5cm=.9230=.9
       2.2cm/6.5cm=.3384=.3
       1.8cm/6.5cm=.2769=.3
As you know Dad, the Rf is the distance of my component to distance of mobile solution. We measured from the .5cm line to the middle of the bulk of the solution, and divide that by the distance from the .5cm line to the solvent front line. A lot of the solutes stopped before the other solutes. This is due to their mass. While the lighter mass dissolves quicker, the heavier mass dissolves slower. The qualitative data that was observed in this experiment somehow used the same three different color pigments. For example in the Crazy Art/ Alcohol , the blue on #10 got darker, #9 went from and orange/yellow to a pink, and the black marker color on #6 went from black to brown to orange to red to purple, then blue. The reason why some of the dyes traveled further  than others is simply due to the chemical composition of mass. As I said before, lighter mass is quicker travel, when denser mass causes a slower travel speed. The chemical components of the solutions also played a key role to why some of the solutes traveled slower than than of others. This is due to nonpolar and polar attractions.
THis lab helps reinforce my previous understandings about chemical/physical changes and properties. We didn't use any type of chemical change or properties, because we were dealing with solubility. Which you know, Dad, is ALWAYS a physical combination of matter. We also reflected on matter classification and how matter affects the solubility and distance the pigments travel. And the separation techniques, were physically noticeable. We were able to separate the dyes from each other . Well, in other words we had fun. It was a neat experiment to start our class on. See you next time,


Love,
Mason




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