Presentation on theme: "Paper Chromatography And Rate of Flow. What is Chromatography? Chromatography is a useful method for separating mixtures. The components of a mixture."— Presentation transcript:
Paper Chromatography And Rate of Flow
What is Chromatography? Chromatography is a useful method for separating mixtures. The components of a mixture are not chemically combined (or bonded). Therefore, they can be separated.
What is Chromatography? Many mixtures, such as food coloring and ink, consist of two or more dyes blended together. After completing a paper chromatography, you will see a pattern of colors appear. Each color or shade of color will be a single component of the whole mixture. These dyes dissolve at different rates.
Why do the Dyes Separate These dyes dissolve at different rates because of their densities and size. The smaller the dye size the further it will travel FULL BLASTHow will these rocks be arranged after the fireman turns on his hose FULL BLAST? Direction of Flow
What about the distance traveled? The distance that a component travels is a property of the dye and the solvent (the liquid that is dissolving the ink). This distance is unique for each dye in each solvent. (as long as you use the same solvent, the dye will always travel at the same rate.)
Rate of Travel The rate at which the components travel from the Origin to the Finish Line is call the Rate of Flow. (It is abbreviated as R f ). Finish Line Origin
How to Calculate Rate of Flow 1.Find the center of each component of the dye and mark it on the paper. Finish Line Origin 2.Measure the distance from the Origin to the center of each component of the dye Measure the distance from the Origin to the Finish Line
How to Calculate Rate of Flow Calculate the rate of flow for each component by using the following formula: Distance to the Finish Line RfRf Distance the component traveled = The R f will always be less than or equal to one. If the component of the dye is found closer to the Finish line, the R f will be closer to the number ONE If the component of the dye is found closer to the Origin line, the R f will be closer to the number ZERO
Practice Problem Distance from the Origin to the Center of Dye component = Distance from the Origin to the Finish Line = 5.15 cm 3.45 cm 5.15 cm RfRf 3.45 cm = = 0.67