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This could have caused slight differences in the

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This could have caused slight differences in the distances obtained for the mixture. It could have also caused the final smear to appear less distinguished into individual components. Careful filling of the beaker with solvent could have avoided this error. For the Column Chromatography, a little more than the required solvent was added to the column. This could have caused the dyes to co-elute to a certain degree. However, since this error was noted early in the experiment and fixed, a clear separation could still be obtained as the result. There are many techniques of chromatography used to separate mixtures into its individual components. One thing that can be inferred from this lab is that, eluting solvents is the key to chromatography. Choosing the correct eluting solvents with the proper properties will give accurate separation and purity. Questions :
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1.a) If too much sample is applied to the plate, it will make the spots appear smeared, larger and longer. If too much sample has been placed on the plate than the adsorbent can hold, the sample will move up the plate according to its ability to dissolve in the mobile phase (solvent). This is what causes the long blotch. This will create differences in the retention factor because the separated components will appear to be connected and so one cannot distinguish between individual components, and decipher whether the mixture was separated accurately into its components or not. b) If the solvent’s polarity is high, then the movement of the solvent up the thin layer plates will occur at a quicker rate. All components in the mixture will move with the solvent and there will be no observable separation creating inaccurate R f ‘s that will be of large value. c) If the solvent pool is deep then the mixtures that were spotted on the thin layer plates will bleed off the paper, and dissolve with the solvent. This would not give us an accurate R f value because the mixtures would not travel up the TLC plate with the solvent, and rather dissolve in the solvent pool. d) Forgetting to remove the plate when the solvent reaches the top of the plate will cause difficulty in identifying the distance traveled by the solvent front. The distance traveled by the solvent front provides the denominator to calculate the R f value. The R f value provides the distance travelled by the mixture over the distance travelled by the solvent front, providing conclusions about the properties of the mixture and the solvent. Allowing the solvent front to over-develop ton he TLC plate may also cause some or even all of the spots to reach the top of the plate and combine into a blotch, making it hard to distinguish them. In both cases, both variables in calculating the Rf value are affected.
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