Question
What can we say if the Rf values of a reference and a spot match in all solvents? It's proven that the mixture contains the reference compound It's certain that the mixture does not contain the reference compound It's likely that the mixture's only component is the reference compound It's very likely that the mixture contains the reference compound
Answer
4.1
(274 Votes)
Tabitha
Elite · Tutor for 8 years
Answer
It's very likely that the mixture contains the reference compound.
Explanation
Rf (Retention factor) values demonstrate how far a particular substance travels relative to the total distance traveled by the solvent. When the Rf values of a reference and a spot match in all solvents, this represents a correlation or match in behavior of these substances. The recognition of unknown substances can be conducted by comparing indexed Rf values to those from standard reference substance in identical circumstances. Three scenarios can occur when comparing Rf values: the Rf values match exactly, are moderately close, or don't match at all. 1. Exact Matching of Rf values: When an unknown substance’s Rf value exactly matches with the reference's Rf value for all solvents, this indicates high likelihood that the reference substance is similar to our sample spot in the mixture. 2. Impreciseness of Rf Analysis: On the flip side, it is important to remember that chromatography is meant to indicate possible identities of mixtures (& guessing components) rather than furnishing the statistically strong data that other analytical technics can. Furthermore, due to a variety of facets, there's always minute inconsistencies at a micro-level which we might come across in Rf analyses—solvent concentration inconsistencies, temperature variance, slight deviation in development tenure of chromatogram, utensils and atmosphere uncontaminated, and identical repeat experiments/Accuracy in calculation.Because of such potential inconsistencies, Rf exactitude thus represents high "probability" of same substance rather than a foolproof omnipresence. Hence we can say that it’s "very likely", rather than "certainly acknowledged" that the reference compound is the same as our targeting substance.