why ascending paper chromatography technique is preferred if Rf values are close
Answers
Answer:
In ascending technique the chromatogram is attached in a way that the spot is touched with the solvent where the solvent is at the bottom. The development of the chromatogram or the separation of the spot is against the gravity. This is why this is termed as ascending technique
Explanation:
Rƒ value, solutes, and solvents
The retention factor (Rƒ) may be defined as the ratio of the distance traveled by the solute to the distance traveled by the solvent. It is used in chromatography to quantify the amount of retardation of a sample in a stationary phase relative to a mobile phase.
In ascending technique the chromatogram is attached in a way that the spot is touched with the solvent where the solvent is at the bottom. The development of the chromatogram or the separation of the spot is against the gravity. This is why this is termed as ascending technique.
Answer:
In ascending technique the chromatogram is attached in a way that the spot is touched with the solvent where the solvent is at the bottom. The development of the chromatogram or the separation of the spot is against the gravity. This is why this is termed as ascending technique.
Explanation:
RF value is the degree of retention of a component retardation factor. RF value does not have units since the both lower and upper cases are in distance. Here the distance is measured up to the center of the spot.
RF value = (Distance traveled by the component) / (Distance traveled by the mobile phase)
The mobile phase travels up to the level of solvent front. We must carefully observe whether the mobile phase develops over the level of solvent front. RF indicates the relative rate of movement of a solute and the solvent. RF value is a characteristic for a given substance under given conditions.