because the colours would mix together, making the results unreliable
If the solvent level reaches the pencil line where the spots are, it can dissolve the compounds in the mixture, causing them to spread out and overlap. This can lead to inaccurate results and difficulties in analyzing the separated components on the chromatogram. It's important to maintain the separation of the compounds on the chromatography plate for clear identification.
Submerging the chromatography paper above the pencil line would cause the solvent to rise above the line, potentially leading to the ink or pigment above the line to dissolve and be carried upwards with the solvent. This can result in the separation of different components within the ink or pigment.
If the solvent is above the level of the initial sample spots in a chromatography experiment, it can lead to the sample being dissolved or dispersed throughout the solvent, causing smudging of the spots and inaccurate separation of components. This can result in poor resolution and difficulty in analyzing the components present in the sample.
If the colored spot is below the level of the solvent, the spot will simply dissolve into the solvent.Chromatography works because the solvent climbs up the 'column' by capillary action, picking up the colored spots along the way and dragging them along. Because of the chemistry of the colors and the solvents, some of the colors in the spots are easier to drag along the column than others, and move along faster.
Pencil is commonly used to mark TLC (thin layer chromatography) plates because it is chemically inert and does not interact with the substances being separated. It also adheres well to the surface of the TLC plate and does not dissolve in the developing solvent, allowing the spots to remain visible throughout the separation process.
If the solvent level reaches the pencil line where the spots are, it can dissolve the compounds in the mixture, causing them to spread out and overlap. This can lead to inaccurate results and difficulties in analyzing the separated components on the chromatogram. It's important to maintain the separation of the compounds on the chromatography plate for clear identification.
If the solvent is above the level of the initial sample spots in a chromatography experiment, it can lead to the sample being dissolved or dispersed throughout the solvent, causing smudging of the spots and inaccurate separation of components. This can result in poor resolution and difficulty in analyzing the components present in the sample.
Submerging the chromatography paper above the pencil line would cause the solvent to rise above the line, potentially leading to the ink or pigment above the line to dissolve and be carried upwards with the solvent. This can result in the separation of different components within the ink or pigment.
The spots on the TLC plate should be placed about a cm from the bottom of the plate. Then solvent should then fall about half-way between these spots and the bottom of the beaker.
If the colored spot is below the level of the solvent, the spot will simply dissolve into the solvent.Chromatography works because the solvent climbs up the 'column' by capillary action, picking up the colored spots along the way and dragging them along. Because of the chemistry of the colors and the solvents, some of the colors in the spots are easier to drag along the column than others, and move along faster.
By placing the spot above the level of the solvent in the beaker, you slow the flow of solvent which results in improved separation of the components in the spot. If you placed it below the level of the solvent in the beaker, the solvent would just flow at a much faster rate and instead of separating the components in the spot, they would simply be washed away.
If the original spots were below the level of developing solvent then the components of the spotted sample would dissolve into the solvent and no spots would be seen upon analysis because all of the sample is dissolved in the developing solvent. hope this helps. good luck in o. chem!
i have no idea
Pencil is commonly used to mark TLC (thin layer chromatography) plates because it is chemically inert and does not interact with the substances being separated. It also adheres well to the surface of the TLC plate and does not dissolve in the developing solvent, allowing the spots to remain visible throughout the separation process.
I assume you are talking about thin-layer chromatography. If the spots are submerged in the solvent, they will dissolve into it and become so diluted that they will most likely be undetectable. Plus, they will elute as a band, not as a spot. Your solvent will also be contaminated.
Solvent should never touch the end of a TLC plate because it can cause the sample spots to dissolve or run off the plate, leading to poor separation and inaccurate results. If the solvent reaches the edge, it can also disrupt the capillary action necessary for the effective movement of the solvent front. Maintaining a proper solvent level ensures optimal chromatography and clearer visualization of the separated compounds.
If the chromatogram is left running for an extended period, the pigment spots may continue to separate as the solvent carries them further along the stationary phase. This could lead to increased resolution between the different pigments, but if left too long, the spots may become too diffuse and potentially merge into one another. Additionally, excessive time might cause the solvent front to reach the end of the chromatogram, resulting in a loss of resolution and clarity.