Why is it better to develop a Chromatogram in a covered container?

Question

Answers in plain basic english cus im very confused at the moment. Thanks

Answer 1

Well.......here goes. This experiment relies on the solvent solution being absorbed into the paper, and climbing upwards. This then allows the separation of the test material / substance, which follows the solvent solution. Most solvents will quickly evaporate when introduced to the air, so for more accurate results, and an overall truer picture, the container should be sealed.

Answer 2

As the solvent is "creeping" up the solid support by capillary action, there is a tendency for the solvent to evaporate. In a covered container, the air inside is saturated with the vapours of the solvent. The result of this is that no more solvent can evaporate from the solid support (into an already saturated environment) allowing the solvent front to move freely up the support and in doing so, properly separate the components in your mixture. In an uncovered container, the solvent will evaporate from the support as the solvent front advances giving rise to reduced distance of the solvent front and inability to separate the components in the mixture you applied to the chromatogram.

Answer 3

the solvents used are generally volatile and would evaporate in the time taken to run the chromatogram.

Answer 4

So that there is no contamination from the air...;