Why do some compounds move further in chromatography?

Why do some compounds move further in chromatography?

Larger molecules take longer to move up the chromatography paper or TLC plate, whereas smaller molecules are more mobile. Polar molecules will be more strongly attracted to polar solvents, and so would move further if a polar solvent was used as opposed to a non-polar solvent.

Why do substances move different amounts up the paper?

The different dissolved substances in a mixture are attracted to the two phases in different proportions. This causes them to move at different rates through the paper.

Why did some inks move a greater distance?

Why did some inks move a greater distance? The ink least readily absorbed by the paper would then travel the farthest from the starting mark. You can conclude from this information that the different pigments were absorbed at different rates.

Why do some substances move up the stationary phase faster?

Higher the adsorption to the stationary phase, the slower the molecule will move through the column. Higher the solubility in the mobile phase, the faster the molecule will move through the column.

Why do some substances not move up chromatography paper at all?

Because they spend more time dissolved in the stationary phase and less time in the mobile phase, they aren’t going to travel very fast up the paper. The tendency for a compound to divide its time between two immiscible solvents (solvents such as hexane and water which won’t mix) is known as partition.

Why do samples move at different speeds in chromatography?

Why do some amino acids travel different distances in chromatography?

The different amino acids move at differing rates on the paper because of differences in their R groups. The rate of movement of a biomolecule during paper chromatography is reported as its relative mobility (Rf).

How does the solvent move up the chromatography paper?

Capillary action makes the solvent travel up the paper, where it meets and dissolves the ink. The dissolved ink (the mobile phase) slowly travels up the paper (the stationary phase) and separates out into different components.

Why do some substances not move up chromatography paper?

Click to see full answer. In this manner, why do some substances not move up chromatography paper? Because they spend more time dissolved in the stationary phase and less time in the mobile phase, they aren’t going to travel very fast up the paper.

What is the difference between paper chromatography and chromatography?

Chromatography relies on two different ‘phases’: the stationary phase, which in paper chromatography is very uniform, absorbent paper the mobile phase is the solvent that moves through the paper, carrying different substances with it The different dissolved substances in a mixture are attracted to the two phases in different proportions.

What is the mobile phase in paper chromatography?

Often for paper chromatography the mobile phase is a mixture of water and an alcohol. This mobile phase is fairly polar, but less polar than the stationary phase. Thus as the mixture moves up the paper by capillary action, the more polar components will travel up the paper more slowly than polar ones.

How do you separate pigments in paper chromatography?

In paper chromatography different pigments can be separated based on their solubility, or their ability to dissolve in water. The more soluble a pigment is, the more readily it will dissolve in the mobile phase and the farther it will usually travel as it is carried by the water being absorbed into the paper.