they interact more with the silica gel, thus travel less than non-polar compounds. Resulting in a lower Rf value.
Rf Value - It tells you the affinity that the compound has to the solvent...High Rf = little or no polar groups and low Rf = more polar groups. Question: In TLC (thin-layer chromatography) when the compound has a high Rf the solvent is: a. less polar b. Is more polar Answer: a. less polar
The Rf value will vary some depending on the exact conditions. Using a silica plate and a moderately polar solvent (dichloromethane or a mixture of toluene/ethyl acetate) you will get an Rf of 0.4-0.5.
If you'll take a look at its structure benzophenone is polar but during our laboratory we were able to determine if it's polar or non-polar by TLC. The TLC plate was developed in a mixture of petroleum ether and ethyl acetate with a 9:1 ratio respectively. This would mean that the solvent used is non-polar due to the large amount of petroleum ether. Finally our group was able to determine the Rf value of benzophenone and we found out that it has an Rf value of 0.4737 so this would mean that benzophenone is non-polar because its Rf value is near to 1.
The Rf values do not indicate the solubility of a substance. The Rf value or retardation factor is the ratio of the distance traveled by the center of a pot to the distance traveled by the solvent front in chromatography.
Response Details:1) factor that affects the Rf value of TLC is the polarity of the solvent. If the solvent is too polar all of the compounds can run right up the plate resulting in poor separation.2) The RF value is used to established the identity of the spots of TLC plate.3) The RF value is ratio of the distance the solvent travels to the distance compound travels.4) The factors can affect RF values. The absorbent uniformity on the thin layer plate, same concentration(spotting is too weak or strong), room temperature during the mobile phase and development distance of the solvent during the mobile phase can all affect the results.5) Multiple solvent system are necessory when utilizing TLC for identification purposes.Response Details:1) factor that affects the Rf value of TLC is the polarity of the solvent. If the solvent is too polar all of the compounds can run right up the plate resulting in poor separation.2) The RF value is used to established the identity of the spots of TLC plate.3) The RF value is ratio of the distance the solvent travels to the distance compound travels.4) The factors can affect RF values. The absorbent uniformity on the thin layer plate, same concentration(spotting is too weak or strong), room temperature during the mobile phase and development distance of the solvent during the mobile phase can all affect the results.5) Multiple solvent system are necessory when utilizing TLC for identification purposes.
Rf Value - It tells you the affinity that the compound has to the solvent...High Rf = little or no polar groups and low Rf = more polar groups. Question: In TLC (thin-layer chromatography) when the compound has a high Rf the solvent is: a. less polar b. Is more polar Answer: a. less polar
The Rf value of Lycopene is between 0.4 and 0.6. The best mobile phase for Lycopene is a mixture of a polar and non-polar solvent.
the volatility of any unknown compound can be known by comparison method between the compound whose volatility is known by the use of paper chromatography. since the high volatile compound has less or no adsorptions to the stationary phase of the parer (the compound is less polar or non-polar) it will move high with the solvent, thus, having high Rf value. The polar compound or less volatile compound will have less Rf value. The conclusion therefore, can be made from the differences in their Rf values
Acetaminophen will have Rf value of about 0.4 and ibuprofen will have Rf value of about 0.6 if the non polar solvent used is ethanol.
The Rf value will vary some depending on the exact conditions. Using a silica plate and a moderately polar solvent (dichloromethane or a mixture of toluene/ethyl acetate) you will get an Rf of 0.4-0.5.
If you'll take a look at its structure benzophenone is polar but during our laboratory we were able to determine if it's polar or non-polar by TLC. The TLC plate was developed in a mixture of petroleum ether and ethyl acetate with a 9:1 ratio respectively. This would mean that the solvent used is non-polar due to the large amount of petroleum ether. Finally our group was able to determine the Rf value of benzophenone and we found out that it has an Rf value of 0.4737 so this would mean that benzophenone is non-polar because its Rf value is near to 1.
Acetaminophen's solubility: 0.1-0.5 g/100 mL at 22 C (Very slightly soluble) Phenacetin's solubility: 0.076 g/100 mL Acetaminophen contains Amide & Alcohol groups, thus makes it really polar whereas Phenacetin contains Ether & Amine that are less polar.
my eluting in more polar solvents
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.
The Rf values do not indicate the solubility of a substance. The Rf value or retardation factor is the ratio of the distance traveled by the center of a pot to the distance traveled by the solvent front in chromatography.
Rf is about .45
Response Details:1) factor that affects the Rf value of TLC is the polarity of the solvent. If the solvent is too polar all of the compounds can run right up the plate resulting in poor separation.2) The RF value is used to established the identity of the spots of TLC plate.3) The RF value is ratio of the distance the solvent travels to the distance compound travels.4) The factors can affect RF values. The absorbent uniformity on the thin layer plate, same concentration(spotting is too weak or strong), room temperature during the mobile phase and development distance of the solvent during the mobile phase can all affect the results.5) Multiple solvent system are necessory when utilizing TLC for identification purposes.Response Details:1) factor that affects the Rf value of TLC is the polarity of the solvent. If the solvent is too polar all of the compounds can run right up the plate resulting in poor separation.2) The RF value is used to established the identity of the spots of TLC plate.3) The RF value is ratio of the distance the solvent travels to the distance compound travels.4) The factors can affect RF values. The absorbent uniformity on the thin layer plate, same concentration(spotting is too weak or strong), room temperature during the mobile phase and development distance of the solvent during the mobile phase can all affect the results.5) Multiple solvent system are necessory when utilizing TLC for identification purposes.