Chromatography lab report Paper chromatography lab report Paper, and produce meaningful results without experiencing thin-layer chromatography lab. Because of separating out materials used for separating organic compounds. See also gas chromatography earlier name was high pressure liquid mobile phase.
Answer — Paper chromatography is a form of liquid chromatography where the components of a mixture of organic compounds get separated as unique spots by unidirectional flow of the developing liquid mobile phase solvent mixture over the filter paper to which a spot of the sample is applied.
The distance travelled by each component is specific under the given set of operational conditions. Question 2 — Why the developing solvent mixture is prepared fresh before use? Answer — The developing liquid phase comprises of a pure solvent but more often it is a mixture of two or more solvents in specified proportions.
In case solvents are mixed and stored for long periods there could be loss of volatile component which will alter the mixing proportions. Why is it necessary to cover the developing chamber during the paper development?
Answer — During the chromatogram development chamber is covered. This is essential as the environment inside the chamber should remain saturated with the solvent vapour.
Development times can vary from about an hour to several hours and a saturated environment prevents losses due to evaporation Question 4-What are the common techniques used for detecting colourless spots?
Answer — It is easy to distinguish coloured spots visually but for colourless compounds alternate techniques need to be adopted which can be specific or non-specific.
A common non-specific method is suspension of developed chromatogram in iodine vapour. Most organic compounds show up as brown spots. The sheet is viewed in a UV Viewing cabinet under nm and nm wavelength lamp illumination. On observation the spots need to be carefully marked with a pencil for Rf calculations.
Under specific methods amines and amino acids are observed by spraying heated paper on development with 0. Deep blue or purple spots begin to appear. Question 5— Why should the samples have reasonable solubility which is neither too high or too low in the developing solvent mixture Answer — The samples should have a medium solubility in the developing solvent mixture.
Too high a solubility will lead to transfer of the component alongwith the solvent front and on the other hand if the solubility is too low the component will not be carried by the solvent mixture and will remain close to the initial applied spot.
In either case the resolution of the mixture components will be low. Thus reasonably good resolution can be obtained for medium solubility of compounds in the solvent mixture.
Question 6-What information you get from the Retardation factor value? Answer — Retardation factor Rf is a measure of the separation of a particular component.
A value of 0 indicates no separation has taken place and 1 represents that the component has moved entire length alongwith the solvent front. In case two spots have same value of Rf it indicates that they are not resolved.
At least a difference of 0. Question 7 — Can you remember the various paper chromatography techniques? Answer — Paper chromatography separations are classified in accordance with the direction of flow of mobile phase along the filter paper.
Ascending paper chromatography — the carrier liquid moves from bottom upwards. Descending paper chromatography — the carrier liquid trough is on top and mobile phase moves downward on the filter paper. Ascending — descending paper chromatography — The paper is rolled downward over the rod at the top.
On reaching the top in ascending mode it starts downward movement in the next phase. The spots spread across the sheet and closely overlapping spots get resolved.
Circular paper chromatography — the mobile phase moves radially outwards from the centre of a circular piece of paper.Chromatography lab Purpose: To separate food colorings into their component dyes using paper chromatography. Materials: Chromatography paper, Food coloring, Ruler, Pencil, Solvent solution, Test tubes, Test tube rack.
Dye Chem DL3. Abstract: The goal of this experiment was to use different dyes to determine the Rf value. Chromatography is done to determine the presence of a mixture in a substance. In this experiment different dyes were used such as McCormick food coloring, M&M’s, Kool .
Chromatography is the process of physically separating molecules in a mixture. The two main components of chromatography are the stationary phase and the mobile phase.
The mobile phase is always the solvent, and the stationary phase, in this lab, is the paper that was put in the solvent. Food Dye Chromatography by on Prezi June 11th, - 1 Cut a piece of chromatography paper and using a ruler Forensics Ink Chromatography Lab November 12th, - Forensics Ink Chromatography Lab Materials Lab 2 Paper Chromatography Free Essays PhDessay com November 16th, - When Mary did her pre lab she measured D and L in.
Separations: Chromatography of M&M and Ink Dyes Almost all substances we come into contact with on a daily basis are impure; that is, they are mixtures. Similarly, compounds synthesized in the chemical laboratory are rarely produced pure.
Chemistry 11 Santa Monica College Paper Chromatography: Separation and Identification of Five Metal Cations Objectives Known and unknown solutions of the metal ions Ag+, Fe3+, Co2+, Cu2+ and Hg2+ will be analyzed using paper chromatography.