Separating and Identifying Food Dyes by Paper Chromatography PDF

Preview

Summary

lab report...

Description

Separating and Identifying Food Dyes by Paper Chromatography Partner: Brianna brackett Date: 2-17-2016 Purpose:  The main purpose of this lab is to separate a mixture into its components by using paper chromatography, and identify them by calculating the retention factor, Rf. Principle:  Rf = Di / Ds; where the retention factor, Rf, is the distance travelled by the spot, Di, divided by the distance travelled by the solvent front, Ds. Procedure:  We measure 7-mL of solvent and put it in a beaker. Then, we use one piece of chromatography paper. We draw two straight lines on it; one line is 1-cm from the bottom, and the other line is 1.5-cm from the top. The distance between the two lines is Ds. After that we label our marks, using pencil, in order: B1, B2, Unk #1, Y5, Y6, Unk #2, R3 and G3. We have to make sure that the distance between each two colors is 1.5-cm. Then, we use spot plate and place one drop of the six pure dyes and the two unknown dye mixtures. To spot each dye onto the chromatography paper, we use wooden sticks. Once the paper was marked we waited 10 minutes to make sure the dyes were fully dry, and then carefully rolled it, stapled the two ends together, and placed it in the beaker with the solvent. When the solvent front is about 1.5-cm from the top of the paper, we remove the paper from the beaker. We finally had to measure the distance between each color, and find out the colors of the unknown mixtures.

Separating and Identifying Food Dyes by Paper Chromatography By: Mirna Elhawafri Partner: Brianna brackett Date: 2-17-2016 Errors:  There are a lot of errors that could happen while doing this experiment. We should use pencil to make marks on the paper not felt tip pen, because the pencil does not react with the solvent unlike the felt tip pen.  We also should watch the development of the experiment carefully, so that the solvent front does not reach to the end of the paper because that will mess up the calculations.  The beaker should be covered till the end of the experiment to prevent the evaporation of the solvent.  Before placing the paper inside the beaker, we should make sure that the level of the solvent is lower than the spots on the paper, so that they do not dissolve in the solvent.  The paper also should be placed in the center of the beaker, so that the colors on the paper do not stick on the sides of the beaker....