Chromatography Lab Answers Purpose The purpose of the experiment is to determine the specific types of pigments found in a beat leaf and in a spinach leaf by using paper chromatography and two solvents: Hypothesis If a water soluble solvent is present, then there will be the movement of only the water soluble pigments up the chromatography paper. Through capillary action these pigments will travel up the paper until the bonds between the water and pigment become so weak that the pigment must break the attraction and leave itself imprinted at a certain height up the paper. Therefore, they will remain at the concentrated area unless a lipid soluble solvent is present.
Today I will be writing about a Chromatography lab, how it was performed, the results and the analysis.
This Chromatography lab was done to identify pigments in different colored leaves and to evaluate the relationship between the pigments and photosynthesis. Chromatography allows a sample, the solute, to be separated out into the samples different pigments and colors through the use of a solvent and capillary action.
Chromatography shows what substances and pigments are within a mixture. However, for chromatography to occur, the correct solvent must be present, a mixture must be able to be separated into differing pigments and finally the correct type of paper must be used to allow capillary action to occur.
Capillary action is when solvent flows up a narrow space or piece of paper in opposition of gravity. Solvent helps separate the individual pigments in a mixture and the distance the solvent travels also helps to find the Rf value. Rf value stands for the the Relative Mobility Factor.
Rf is a characteristic that is specific to a certain substance and is calculated by Dunknown divided by Dsolvent, which stands for Distance solute traveled divided by Distance solvent traveled. Because Rf values are consistent across consistent conditions, the value can be used to identify a substance by all scientists.
So, using this knowledge, chromatography was performed on two different leaves, one green and one red. The chromatography paper was cut and set up and the solute was added to the beaker. Then, the pigment from each leaf were transferred onto two different chromatography papers by pressing a quarter into the leaf, resulting in the pigment transferring onto the paper.
The tip of the chromatography paper was then put into the solvent and the experiment sat for minutes. Red leaf chromatography Green leaf chromatography After minutes, the chromatography paper was taken out of the beaker and analyzed by measuring solvent distance and the various distances for each pigment present.
Red leaf chromatography after 15 minutes Green leaf chromatography after 15 minutes The Rf values were then calculated for each pigment for each leaf and the results were the following: Rf values are in the right column Rf values are in the right column These results show that the Green leaf has mainly green pigment Chlorophyllwhile the Red leaf has all pigments.
The lab itself was fairly easy to set up, however there were various inconsistencies such as the length and width of the chromatography paper used, the time allotted for the experiment to occur and the amount of pigment transferred onto each paper, which all contribute to experimental error.
You can try this lab at home, check out this YouTube video to see how you can perform this experiment with a pen. This experiment gives insight into what pigments different colored leaves are composed of and how calculating the Rf value can indicate what pigment it is.
The initial data from chromatography can lead to many other experiments and connections made between photosynthesis and leaf pigmentation. One experiment leads to many more questions!Plant Pigments and Photosynthesis Lab Report Background: (Part A)Paper chromatography is a useful technique for separating and.
identifying pigments and other molecules from cell extracts that contain a complex mixture of molecules.4/4(15). Chromatography Lab Answers Purpose The purpose of the experiment is to determine the specific types of pigments found in a beat leaf and in a spinach leaf by using paper chromatography and two solvents: water soluble solvent and lipid soluble solvent.
Paper chromatography is normally used to separate mixtures of different molecules since capillary action happens and allows the molecules of each pigment to attract to one another and to the paper and thus, move up the paper (“Lab Report On Plant Pigments and Photosynthesis Biology Essay”). The purpose of this lab was to see separate and identify the pigments of spinach cells through the use of paper chromatography.
Through this lab, one can understand the rate of photosynthesis and absorbency rate of chloroplasts in different light intensities. The Separation and Identification of Plant Pigments by Paper Chromatography and the Determination of the Absorption Spectrum for those Pigments Introduction: Photosynthesis, the conversion of light energy from the sun into chemical energy in the form of organic molecules, is the sole process by which energy enters the biosphere.
%(18). The chromatography aspect of this lab shows what pigments are in a sample of blue-green algae and spinach. Factors that affect the outcome are the mass of each pigment, and its affinity for the paper used, and how soluble the pigment is in the solvent.