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What would happen if the Spot of origin is lowered into the solvent in chromatography?
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!
What else can I help you with?
How is rf factor in chromatography calculated?
The Rf factor in chromatography is calculated by dividing the distance the compound travels by the solvent front by the distance the solvent front traveled from the origin. The formula is: Rf = Distance traveled by compound / Distance traveled by solvent front. The Rf value is useful for identifying compounds based on their relative mobility in a given solvent system.
What is propelling force in paper chromatography?
The propelling force in paper chromatography is capillary action, where the solvent moves through the paper due to the attraction between the solvent and the paper fibers. This causes the components in the sample to separate as they are carried at different rates along the paper.
How so you measure the solvent front?
The solvent front is usually measured as the distance from the origin (baseline) to the solvent front edge on a chromatography plate or column. This distance can be measured using a ruler or caliper for accurate quantification. It is important to ensure the accuracy of this measurement to calculate Rf values correctly.
What does a small Rf number tell you about the characteristics of the moving molecules along the chromatography paper?
A small Rf (retention factor) number indicates that the molecule moves a shorter distance relative to the solvent front, suggesting a stronger interaction with the stationary phase. This can imply that the molecule is more polar or has a higher affinity for the stationary phase in the chromatography process.
What is substance that have 0.803 Rf value?
The Rf value of a substance is a measure of its migration distance during chromatography. A substance with an Rf value of 0.803 would mean that it traveled 80.3% of the total distance from the origin to the solvent front during the chromatography process. The specific identity of the substance would depend on the experimental conditions and the properties of the compound.
How is rf factor in chromatography calculated?
The Rf factor in chromatography is calculated by dividing the distance the compound travels by the solvent front by the distance the solvent front traveled from the origin. The formula is: Rf = Distance traveled by compound / Distance traveled by solvent front. The Rf value is useful for identifying compounds based on their relative mobility in a given solvent system.
What is propelling force in paper chromatography?
The propelling force in paper chromatography is capillary action, where the solvent moves through the paper due to the attraction between the solvent and the paper fibers. This causes the components in the sample to separate as they are carried at different rates along the paper.
Why some substances in chromatography will travel futher up the paper?
Substances travel further up the paper in chromatography due to differences in their affinity to the mobile phase (solvent) and the stationary phase (paper). Substances that have higher affinity for the solvent will move faster and farther up the paper, while those with higher affinity for the stationary phase will travel slower and remain closer to the origin.
Why are Rf values always less than 1?
Rf values are distance of substance from origin divided by distance of solvent front from origin. As the substance travels with the solvent, the solvent will always have a greater or equal value to the distance travelled by substance. This means the highest value of Rf is 1.
How so you measure the solvent front?
The solvent front is usually measured as the distance from the origin (baseline) to the solvent front edge on a chromatography plate or column. This distance can be measured using a ruler or caliper for accurate quantification. It is important to ensure the accuracy of this measurement to calculate Rf values correctly.
What does a small Rf number tell you about the characteristics of the moving molecules along the chromatography paper?
A small Rf (retention factor) number indicates that the molecule moves a shorter distance relative to the solvent front, suggesting a stronger interaction with the stationary phase. This can imply that the molecule is more polar or has a higher affinity for the stationary phase in the chromatography process.
What is substance that have 0.803 Rf value?
The Rf value of a substance is a measure of its migration distance during chromatography. A substance with an Rf value of 0.803 would mean that it traveled 80.3% of the total distance from the origin to the solvent front during the chromatography process. The specific identity of the substance would depend on the experimental conditions and the properties of the compound.
Is rf value is negative or not?
The RF value, or retention factor, is a measure used in chromatography to indicate the relative distance traveled by a compound compared to the solvent front. By definition, RF values range from 0 to 1, where 0 indicates that a compound did not move from the origin and 1 indicates that it moved with the solvent front. Therefore, RF values cannot be negative.
What determines the distance a pigment moves up the paper?
The distance a pigment travels up the paper in paper chromatography is determined by its solubility in the solvent being used, its molecular size, and its attraction to the paper. Pigments that are more soluble and smaller in size tend to move further up the paper, while those with stronger interactions with the paper tend to stay closer to the origin.
How does paper chromatography separate the molecules?
Paper chromatography separates molecules based on their solubility in the liquid solvent. One end of the chromatography paper is dipped into a solvent reservoir which travels up the paper via capillary action. The samples are placed on the bottom of the paper, above the initial solvent line. As the solvent travels up the paper, it dissolves the samples and carries them upwards. Based upon the samples' solubility in the solvent, they travel proportionally further or shorter distances.
How can paper chromatography be used to separate pigments based on their chemical and physical properties?
It is an appropriate technique to use because it separates the pigments, so one can see which pigments are present, even if some pigments are normally hidden to the naked eye.
What would be the consequence of having so much solvent in the developing chamber that it would cover the application?
If the solvent level in the developing jar is deeper than the origin (spotting line) of the TLC plate, the solvent will dissolve the compounds into the solvent reservoir instead of allowing them to move up the plate by capillary action. Thus, you will not see spots after the plate is developed. These photos show how the yellow compound is running into the solvent when lifted from the developing jar.
