• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

An experiment to identify substance X using thin layer chromatography.

Extracts from this document...

Introduction

An experiment to identify substance X using thin layer chromatography. Introduction In this experiment the method being used is chromatography. Chromatography is an important method for finding out more about mixtures. Chromatography allows substances to be separated with a solvent and indicates whether a substance is pure, meaning it contains only one single substance, as opposed to a mixture of substances, allowing for concentrations to be made. By using think layer chromatography (TLC), the aim of the experiment is to find out whether 'substance X' is either Anadin which contains aspirin and caffeine, or Anadin extra, which contains aspirin, caffeine and also paracetamol. Thin layer chromatography is a technique involving the distribution of a mixture of two or more substances between a stationary phase (involving a solid or a liquid) and a mobile phase (involving a solid or a gas). The thin layer of absorbent coated on the chromatography paper is normally a silica get, cellulose or alumina. The mobile phase is a developing liquid. ...read more.

Middle

Helping to remove any toxic fumes produced by the hazardous liquids. Method 1. A strip of chromatography paper was taken and a thin pencil line was made at the bottom of the paper - three equally spaced marks were also made, ensuring that the paper was not touched. 2. Four test tubes were taken and labeled A(aspirin), P(paracetamol), C(caffeine) and X(substance X) 3. 1-2cm� of the drug solvent (Ethanol) was added to each tube. Then carefully shaken from side to side, to ensure the drug samples were dissolved. 4. A spot of solution from each of the drug samples were carefully placed on the chromatography plate using a fresh capillary tube each time. This was repeated three times to ensure enough of the drug sample was placed on the chromatography plate and was then allowed to dry in fume cupboard. 5. 0.5 - 0.75cm� of the developing solvent (Butyl Ethanolate) was poured into a beaker - ensuring that the solvent does not touch the pencil line drawn on the bottom of the plate. Foil was then placed on top of the beaker. ...read more.

Conclusion

Substance X (anadin extra) however had a mixture of the tested substances on the chromatography paper, proving that it was not a pure substance. There was extra spotting on the chromatography paper, which were highlighted by the UV light. These results were anomalies, and were invalid results. Evaluation If the experiment was to be carried out again I would not use capillary tubes, because they are very fine and break easily. Instead I would use a wider piece of chromatography paper and use a drop of solution from a pipette. This would also ensure that the results would be more accurate removing the risk of any anomalous results, as you would be able to ensure that the substance hit the mark correctly, whereas, with the capillary tubes it was needed to be repeated several times to ensure it was place on the chromatography plate. Another change I would make in the experiment is that I would use a larger test tube, or even a small beaker. By doing this you would be able to stir the analgesic, ensuring that it has fully dissolved in the drug solvent. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Inorganic Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

or


Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Inorganic Chemistry essays

  1. Peer reviewed

    Deducing the quantity of acid in a solution

    5 star(s)

    Sometimes the indicator changes colour when the H2SO4 hits the solution in the flask, but then the colour change disappears upon when swirling, so swirling the flask constantly will ensure us that the reaction has occurred. That is why swirling the flask all the time is a very important step.

  2. Analysis of Commercial Aspirin Tablets

    So the calculated value of the no. of moles of and mass of aspirin was smaller than the actual ones. Improvement: Grand the aspirin tablet and dissolve it in a larger volume of solution. Defect 2: -The sample of aspirin may not contain acetylsalicylic acid only.

  1. Gas Chromatography

    Capillary columns, on the other hand, need much less sample, typically around 10-3 ?L. For capillary GC, split/split less injection is used. Have a look at this diagram of a split/split less injector sample. For packed columns, sample size ranges from tenths of a micro liter up to 20 micro liters.

  2. Synthesis of Aspirin

    * Once I place the beaker in the cold water after about 10min it started to crystallize. Once crystallized I had to put it in this machine where it sucked out the excess water. * When I left it over night it turned into crystals, to see if this was pure we had to do the Iron III chloride test.

  1. Fission and Fusion (Open Book paper 2008)

    Explain how each type of reaction produces energy and describe how these reactions are controlled. Outline the main advantages and disadvantages of using fission and fusion processes for generating electricity. Fission Image 2 - fission Source [9] Both of the new nuclei are approximately half the size of the original nucleus.

  2. Ice Lab and its Phase Changes

    Hypothesis: I will hypothesize that "Yes," their will be the same temperature as the phase changes from solid to liquid. The potential energy stays the same and nothing else is contributed. Materials: o Crushed ice o 3 Ice cubes o Thermometer o 1 1000 ml beaker o 1 250ml graduated cylinder.

  1. Flame Test Experiment

    When I put unknown A in the flame it turned yellow from this I could tell it was Sodium, I had confirmed this when I had looked at the internet webpage. This helped me identify unknown A, when I did the same for B I got the colour pink/ lilac, from this I could tell that substance B was Potassium.

  2. The purpose of this experiment was to prepare a sample of Aspirin and measure ...

    on to the small tube and became even hotter recording the temperature. Method All reactions were completed in a fume cupboard for safety. The first step was to add 50g of salicylic acid with 80ml of acetic anhydride in a round bottom flask.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work