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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.
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∙ 15y ago
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∙ 11y agoRf 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.
Read more: Why_is_the_Rf_value_always_less_than_1_in_relation_to_chromatography
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∙ 12y agoThe Rf value is a way of identifying compounds separated by chromatography.
It is obtained by dividing the distance moved by the unknown compound by the distance moved by the solvent.
Since the compound cannot move further than the solvent (because it is carried along by the solvent), the Rf value cannot be greater than 1.
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Is it possible to have a Rf value greater than 1?
No, it's not possible to have an RF value greater than one. Rf values are a ratio of the distance a spot has traveled to the total distance of the solvent front. Since the distance of the front is always greater than the distance of a spot, the Rf value is always less than 1.
What does a frequency of recombination of 50 percent indicate?
A recombination frequency is a measure of how likely it is that two genes are linked. It will also tell how likely it is that a crossing over event will occur between those two genes. Thus, for an RF=50% it is random as to whether or not the genes will be inherited together or whether crossing over will separate them (i.e. they independently assort). Traditionally, following Mendel's Second Law (that alleles of genes independently assort), an RF=50% means that the two genes are on different chromosomes; a slightly more complicated corollary is that the two genes need not be on different chromosomes but may be on the same chromosome just very far apart from each other. Thus, the smaller the RF (maximum RF is 50%), the more likely it is that two genes are linked.
what are the following processes releases energy to be used by a cell?
Chemical reactions that release energy are called exergonic. Cellular processes that release energy are called catabolic, or catabolism. {I remember this by thinking 'What does a cat do with its claws to your furniture - it breaks things down.' Also, anabolic steroids are for 'building up'.} The main energy producing catabolic reactions occur using Respiration that releases usable biochemical energy in the form of Atp.
Do all leaves extracts contain the same pigments?
Yes, all leaves contain the same pigments but they contain it at different concentrations. Like in the summer all leaves are green (they all contain chlorophyll) and in the autumn, almost all leaves turn brown, orange, or yellow (contain carotenes, lutein, or xanthophylls). These are only seen when the chlorophyll breaks down like in the autumn, but they are not seen when the chlorophyll comes back like in the spring and summer.
Can you touch fire?
Yes, but it would hurt very badly. Fire, like all things, is composed of matter. In fire's case, that matter is called plasma (as opposed to solid, liquid or gas). All matter takes up space and therefore can be touched.
Is it possible to have a Rf value greater than 1?
No, it's not possible to have an RF value greater than one. Rf values are a ratio of the distance a spot has traveled to the total distance of the solvent front. Since the distance of the front is always greater than the distance of a spot, the Rf value is always less than 1.
If two samples have identical Rf values does this mean that they are necessarily identical molecules Explain?
No. The molecules MAY (and probably are if you are presented with this situation in school/college lab courses) be identical but just the Rf values is not enough information to determine, you must conduct additional tests. Two different molecules can have the same Rf value.Compound A will always have an Rf of X in solvent M. Compound B will always have and Rf of Y in solvent M. But, Rf X can be equivalent to Rf Y without compounds A and B being identical.
What does it mean when the Rf value is less then 0?
When the Rf value is zero, it generally refers to the position of the substance in the chromatogram. This means it did not move of that origin point.
Why are Rf values used?
Rf values are used mainly for simplicity. These values are generally easier to use to obtain percentages between a couple objects instead of using values that are already established.
Why polar compounds have less Rf value?
they interact more with the silica gel, thus travel less than non-polar compounds. Resulting in a lower Rf value.
Why Ni positive 2 and iron positive 3 ions have different Rf values?
Rf values are determined by the polarity of the substance tested. Even though these atoms may have similar electron configuration, it is not identical, and neither are their Rf values.
How would you expect Rf values to change if you went from hexane-ethyl acetate solvent system to ethyl acetate only?
the rf values would increase
How are Rf values used in real life?
Rf values can be used to identify the type of drugs that had been taken by those who went through drug overdose.
What are the significance of values?
Rf Values determine the solubility of a substance with respect to a certain solvent.
What do the Rf values indicate about the relative solubility of the pigment in the the solvent?
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.
Arrange the following compounds in order of increasing Rf values in TLC Anthracene benzil tryphenylmethanol?
The order of increasing RF values in TLC is Benzil, methanol anthracene and tryphenyl.
What is the value of a Reggie Jackson 1988 Score RF baseball card?
Less than 30 cents.
