Paper Chromatography Lab Report

Background: Paper chromatography is one method for testing the purity of compounds and identifying substances. Paper chromatography is a useful technique because it is relatively quick and requires small quantities of material.

The intermolecular forces are pulling the molecules between the stationary phase, the chromatography paper and the mobile phase, the solvent. The molecules of the chromatography paper are trying to pull the molecules to where they are while the molecules of the molecules with them to the top of the paper. 4. Draw a picture of how the chromatography worked. Explain your picture using the following terms: stationary phase, mobile phase and intermolecular forces.

The most polar molecules on a chromatography strip move the least, and the least polar molecules move the most. Out of red dye #40, blue dye #1 and yellow dye #5, the molecules in blue dye #1 have the polarity closest to both isopropyl alcohol, and sodium chloride solutions. Red dye #40 has the most polar molecules, while blue dye #1 has the least polar molecules.

The stationary phase will absorb or slow down different components of the tested solution to different degrees creating layers as the components of the solution are separated. Chromatography was invented by the Russian botanist, Mikhail Tsvet. Chemists use this process to identify unknown substances by separating them into the different molecules that make them up.

Random movement of solute (dissolved particles) and solvent (water molecules) will result in an evenly distributed solution.

Passive transport can occur during osmosis and diffusion. During osmosis, water molecules diffuse down a concentration gradient from an area of high concentration to an area of low concentration through a selectively permeable membrane (Harley et al., 42-44). Tonicity refers to the relative concentration of solutes in a solution. They can be labeled as isotonic, hypotonic, or hypertonic. Isotonic solutions have the same concentration of solutes inside and outside of the cell.

1. Paper Chromatography is a method used for the separation of colors which are also referred to as colored chemicals/substances or pigments. This method is used for experiments, to identify coloring agents and to separate out a compound into its various components.

This happens through a process called diffusion. Diffusion is the movement of molecules from a region of high concentration to a region of lower concentration. (McQuade,

The eluting solvent passed down the column by the gravity and an equilibrium was established between the solute absorbed by the absorbent (silica gel in this experiment) and the eluting solving flowing down. Since the components in the sample had different polarity and they interacted with the stationary phase and the mobile phase differently, the components would be carried by the solvent to a different extent and a separation of the components could be achieved.

Chromatography is a separation technique in which the mixture to be separated is dissolved in a solvent and the resulting solution, often called the mobile phase, is then passed through or over another material, the stationary phase. The separation of the original mixture depends on how strongly each component is attracted to the stationary phase. Substances that are attracted strongly to the stationary phase will be retarded and not move alone with the mobile phase. Weakly attracted substances will move more rapidly with the mobile phase.

The following procedure dealt with a chromatogram. The materials needed are: a pencil, safety goggles, scissors, chromatography paper strip, capillary tube, spinach plant pigment extract, test tube, cork stopper, graduated cylinder, chromatography solvent (alternative isopropyl alcohol), metric ruler, stopwatch or clock with a secondhand, hook/fashioned paperclip, paper towels, test tube rack, and mortar and pestle. First we obtained a strip of chromatography paper and cut it so it would fit inside a test tube (with it barely touching the bottom of the tube). Also, when touching the strip, touch the sides only. Then we attached (firmly) the top of the strip to a hook (or fashioned paperclip at bottom of the cork stopper). Make sure it fits in the test tube. Next we used the pencil to draw a faint line across the strip two centimeters from the bottom tip of the strip. We placed the cork and strip in place, and we put a mark on the test tube one centimeter below the top of the stopper.

Diffusion is the passage of solute molecules from an area of high concentration to an area of low concentration (Campbell & Reece, 2005). An example is ammonia diffusing throughout a room. A solute is one of two components in a chemical solution. The solute is the substance dissolved in the solution. The solvent, the other component, is any liquid in which the solute can be dissolved (Anderson, 2002). Diffusion requires little or no energy because molecules are always randomly moving; this is due to their kinetic energy. Diffusion occurs only when there is an imbalance in the areas of

Chromatography Investigation Chromatography is a highly regarded technique used to separate the components of a mixture. It is based on the principle that each component possesses a unique affinity for a stationary phase and a mobile phase. The components that are more inclined to enter the mobile phase will migrate further on the chromatogram and distinguish themselves from the other components. The type of solvent used in chromatography is known to directly affect the separation of the mixture. In this experiment, thin-layer and column chromatography will be utilized to separate the numerous chlorophyll and carotenoid pigments of a spinach extract.

The movement of water molecules across a semi-permeable membrane is the process of osmosis. If there is a solute and a solvent, each containing different concentration levels, then the water would move along its concentration gradient until each side of the membrane are equal. The water moves because the membrane is impermeable to the solute and the solute concentrations may differ on either side of the membrane. Water molecules may move in and out of the cell, but there is no net diffusion of water. Water will move in one direction or the other, and this is determined by the solute or solvents concentration levels. If the two solutions are of equal concentrations, they will be isotonic. If the concentrations are unequal, the

Gel-Filtration Chromatography is a commonly used method used in order purify a protein from a mixture, by means of separations. Different biomolecules differ in size, or their molecular weight. In the gel matrix inside the chromatography column, there are gel beads which are porous to allow certain sized molecules to enter. The molecules that are able to enter the pores of the gel, are held in stationary phase and will elute from the column later on, these are usually smaller, to medium sized molecules. Larger molecules that are not able to fit in the pores will elute out of the column first, they are involved in mobile phase where they just go straight through the column without interacting with the gel beads. Smaller molecules will have a higher elution volume, while the larger molecules will have a lower elution volume. The volume to elute the protein is inversely proportional to the molecules size.