How is the Rf value for a spot on a TLC plate calculated? What can the Rf value be used for?
And
How is the Rf value for a spot on a TLC plate calculated? What can the...
Determine the Rf value of the substances A, B, and C on the TLC shown. Show your calculation! What will happen if the applied spot is lower than the level of the developing liquid? What will be the result of applying too much compound on a TLC plate? What is the reason that the mobile phase travels up the silica gel plate (TLC plate)? 4. Determine the Rf value of the substances A, B, and Con the TLC shown. Show...
Calculate the Rf value of the spot that corresponds to -carotene on the 7:3 Acetone:Toluene plate. (TLC PLATES ARE CLOSE TO SCALE, NOT ACCURATE REPRESENTATION)
Question 18 (3 points) What is the Rf value for the TLC spot shown? The scale is shown next to the TLC, where each marking is one unit apart. solvent front IIIIIIIIIIIIIII O origin 0 0.50 O 0.45 0.53 0.40
1) Calculate the Rf value of a spot that travels 5.7 cm, with a solvent front that travels 13 cm. 2) A student spots an unknown sample on a TLC plate and develops it in pentane solvent. Only one spot, for which the Rf value is 0.05, is observed. Is the unknown material a pure compound? What can be done to verify the purity of the sample using thin-layer chromatography? 3) You try to synthesize n-hexyl bromide as a product...
A silica gel TLC plate was spotted using compounds A-D and developed in hexane. Spot “B” traveled a distance of 2.0 cm from the solvent front at 4.0 cm, which of the following is a correct way to calculate its Rf value? Spot Distance traveled (cm) A 0.50 B 2.0 C 3.0 D 1.0 Spot B Rfis 4.0 cm/0.20 cm = 2.0 Spot B Rf is 4.0 cm/(4*2.0 cm) = 0.50 Spot B Rfis 2.0 cm/4.0 cm = 0.50 Spot...
For TLC plate separation, why do we use Rf values instead of distance measurements (e.g. the spot travelled 5 cm from the starting line)? What would happen if we compared solvent systems using distances rather than Rf values?
A student calculated the R(f) value for a spot to be 1.05. Why is the value wrong? The progress of a reaction can be followed using TLC as follows: Several TLC plates are prepared by spotting them with the starting compound(s) and the product(s). (each plate is spotted with all the compounds,each in its own spot.) A place on each plate it saved for the reaction mixture.Periodically as the reaction proceeds (for example, every 30 minutes) a prepared plate is...
3. If the TLC plate development had stopped before the solvent front reached the top of the TLC plate (i.e. maybe it reached the middle of the TLC plate when it was stopped, instead): a) Would the Rf values have been affected? If so, how? If not, why not? Give a numerical example to support your answer. b) Would the size of the spots have been affected? If so, how? If not, why not? (Hint: think about the diffusion of...
Which compound should have the highest Rf value on a TLC plate? A acetanilide B nitroacetanilide C dinitroacetanilide
Which compound should have the highest Rf value on a TLC plate? (for Electrophilic Aromatic Substitution: Preparation of p-Nitroacetanilide experiment) A acetanilide B nitroacetanilide C dinitroacetanilide