13/03/09
Testing for negative ions:
To show the presence of various negative ions.
Method and Results;
20/03/09 Presentation IR Spectroscopy Lesson Write-up
IR Spectroscopy – What’s in the Bottle?
IR stands for Infra Red (this is part of the electromagnetic spectrum)
It is used to identify functional groups in organic results.
Alkanes - A hydrocarbon containing only simple C-C bonds.
Alkenes - A hydrocarbon that has 1 C=C bond (double).
Alcohols - An organic molecule that contains an O – H bond.
Aldehydes - An organic molecule that contains a C=O bond. Formed when an alcohol is oxidised.
IR Spectroscopy
IR radiation is shone on the molecules. The bonds absorb energy at different frequencies and start to vibrate.
We can measure the frequency at which the actual bond vibrates and we use it to determine the functional group present.
20\03\09F & 26\03\09 Experiment Lesson Write-up
Coursework Write-up – What’s in the Bottle?
Testing for negative ions:
Results;
Final outcome: A - Iodide (I-)
B - Sulphate (SO42-)
C - Nothing happened
Testing for metals:
Results;
Final outcome: A - Potassium
B - Sodium
C - Not applicable.
Testing for alcohols
Results;
Final outcome: A – Not alcohol
B – Not alcohol
C – Alcohol
Conclusion - From the results that I have gathered from the various tests I have done I have found out that C is an alcohol whilst A and B are not alcohols. I have come to the conclusion that sample A is Potassium Iodide, B is Sodium Sulphate and C is an alcohol.
Evaluation – After spending hours experimenting we really have found out what’s in the bottle. If I was to do this sort of activity again I would take down specific and accurate notes. This is so that when I refer to them I know exactly what I’m doing and I am not confused. Overall, I think coursework was challenging but went well.
Chromatography
What is Chromatography?
Briefly, it is a wide variety of physical steps used to separate complex mixtures.
Why do we do Chromatography?
Chromatography is a technique we use for separating and identifying mixtures that can be coloured or that are coloured. This method can be used in secondary or primary colors in ink experiments.
How do we do Chromatography?
This is how chromatography works; a tiny spot of solution that has the solute on it is put on to a little strip of chromatography paper. This is usually kept about a couple of centimeters away from the bottom of the plate. This sample is absorbed onto the paper. Any substance that reacts or bonds with the paper cannot be measured using this technique. In a sealed container, solvent such as ethanol or water are used; paper is dipped into the solvent ensuring that the spot is above the surface. Paper chromatography takes anywhere from several minutes to several hours.
When is chromatography used in the industry?
Chromatography is used in many ways; following are various uses of chromatography: to find out what is in a solid or a liquid, to determine what unknown substances are. The Police, F.B.I., and other detectives use chromatography when trying to solve a crime. It is also used to determine the presence of cocaine in urine, alcohol in blood, PCB's in fish, and lead in water. Also to test water samples to look for pollution, detect bombs in airports, identify and measure the amounts (volumes) of such drugs as alcohol, used in forensics to compare fibers found on a victim, detecting pesticide or insecticide residues in food, also used in forensics to analyze the dye composition of fibers, separating amino acids and anions, RNA fingerprinting, separating and testing histamines, antibiotics, for separating organic and inorganic compounds so that they can be analyzed and studied, Toxicology, In sports medicine, any illegal drugs will be picked up using chromatographic techniques. (e.g.: Gas chromatography). These are just a few of the uses of Chromatography; there are literally hundreds, if not thousands, of uses for chromatography.
How do we use the results we attain from chromatography?
We analyze the results after development, by matching the corresponding spots to different compounds by locating them by their colour, light, (Triketohydrindane hydrate) or by treatment with vapors.
