A) Why should the jar used to cover the TLC plates becovered? B) Suggest a reaso

Question

A) Why should the jar used to cover the TLC plates becovered?
B) Suggest a reason that TLC plates that are stored in ahighly humid room result in different Rf valuesthan plates that are stored in a dehumidified environment. Hint: consider the structure of the layered material onthe TLC plate and how that material might interact with watermolecules in the air.
C) Why should the "spots" applied to the TLC plate bekept as small as possible?
D) Even if two spots have the sameRf value, we cannot be certain that the two samplesare identical compounds. Suggest a good method to confirmthat the two samples are the same or not the same.
E) Why is TLC a poor technique for the analysis oflow-boiling point liquids? (Hint: low-boiling point meanshigh vapor pressure at room temperature)
B) Suggest a reason that TLC plates that are stored in ahighly humid room result in different Rf valuesthan plates that are stored in a dehumidified environment. Hint: consider the structure of the layered material onthe TLC plate and how that material might interact with watermolecules in the air.
C) Why should the "spots" applied to the TLC plate bekept as small as possible?
D) Even if two spots have the sameRf value, we cannot be certain that the two samplesare identical compounds. Suggest a good method to confirmthat the two samples are the same or not the same.
E) Why is TLC a poor technique for the analysis oflow-boiling point liquids? (Hint: low-boiling point meanshigh vapor pressure at room temperature)

Explanation / Answer

   a) The jar is used to cover the TLC platesbecause it can protected from outer impurities which are in air isnot contact        with the analysingcompound. And one more adventage is the solvent didnot flow outfrom the beaker. b)   Here the major difference in Rf values were observed in the both humidity anddehumidity conditions . In humidity        condition the samplebeing analyse is directly contact with the water molecules but inthe other dehumidity case this         situation is notoccured hence we can see the difference in their Rfvalues on TLC plate. c) The small spots are put on TLC plate because to overcome the adjecent spots merging with each other in the path        of solventflow.That means spots were enlarged in the solvent phase. d) Here in TLC we can not say both the two componentsare same even they had same Rf values . But thebest method      for anlysing such type of componentsis high pressure liquid chromatography. e) this is why because if the solvent is low boilingpoint it can easily flow out from the origene with carring theanlysing component. Hence this is the poor technique for lowboiling liquids.

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