Chromatography is one of the most of import separation techniques used in all Fieldss of chemical science runing from analytical chemists to druggists. The apprehension of how chromatography works and how to run instruments used to transport out the processs is an of import lab technique to larn.
Experiment:
Thin Layer Chromatography. Lab # 10-1
Paper Chromatography. Lab # 10-2
Theory:
Ethyl Acetate-Solvent used in TLC ( nomadic stage ) .
Dichloromethane- Solvent used to fade out all samples used to compare unknown in TLC Silica Gel Plates- TLC plates. Stationary stage
Elemental Iodine- used to stress the musca volitanss on the TLC home bases so we can mensurate Rf. Asprin ( Acetylsalicylic acid ) – First compound used on TLC home base to compare the unknown. Salicylamide ( o-hydroxybenzamide ) -Second compound used on TLC home base to compare unknown. Caffine ( 1. 3. 7-Trimethylxanthine ) -Third compound used on TLC home bases to compare unknown. Acetone- Solvent A used in paper chromatography.
Ethanol- Solvent B used in paper chromatography.
Dithiooxazmide- Spray used to demo to descry on paper chromatography Sodium Diethyldithiocarbamate- Second spray used to demo musca volitanss on paper chromatography Ammonia- Fumes were used to convey about the musca volitanss on the filter paper in paper chromatography.
Consequences:
Unknown in TLC was Aspirin
Unknown in Paper was Nickel
Rf Asprin-5. 5cm/7= . 78
Rf Salicylamide-6. 3cm/7= . 9
Rf Caffine-1. 2cm/6. 3= . 19
Rf Unknown ( TLC ) -5. 5cm/7= . 78
Rf Cobalt solvent # 1-5. 1/6. 5= . 78
Rf Copper solvent # 1-5. 7/6. 5= . 87
Rf Iron solvent # 1=1
Rf Nickel solvent # 1-1. 4/6. 7= . 21
Rf Unknown ( Paper ) solvent # 1-1. 3/6. 5= . 21
Rf Cobalt solvent # 2= . 88
Rf Copper dissolver # 2= . 86
Rf Iron solvent # 2= . 91
Rf Nickel solvent # 2= . 94
Rf Unknown ( Paper ) solvent # 2= . 91
Calculations:
Rf Unknown ( Paper ) solvent # 1-1. 3/6. 5= . 2
Discussion:
In this Lab. I had to run some tests multiple times due to descry non demoing up. The lone one I am still non certain of if I got a definite grade is of Iron in solvent # 1 on the paper chromatography. However. I do non believe this affects my informations because my unknown expressions really similar to another metal. One mistake that was made comparatively systematically was non allowing the dissolver rise high plenty. Although this is a relative mistake. I did non hold clip to allow them go on to lift. The lone test that this caused a job in was in the paper chromatography test with solvent # 2. This was the last test that I ran and was out of clip. I had to draw it out before it was close to the top. The compounds nevertheless ended all at the really top unfinished so I had to generalize where I believed they would stop if I let the solvent rise more. I believe this is still non a job nevertheless due to the fact that my unknown solutions colour. form. and size were all consistent in both solutions. Therefore I do non hold to be so consistent with the keeping factor in order to cognize what my unknown was. If there were other metals whose colour form and Rf was closer to the unknown. this would hold caused a much grater job.
