Which of the following statements is not true? A. In TLC, the relative intensity of the spots is not an accurate indication of the amounts of the compounds present, since the extent of the reaction varies. B. The primary basis of the separation in TLC is polarity C. Rf is calculated by dividing the distance traveled by the solvent by the distance traveled by the solute

Which of the following statements is not true? A. In TLC, the relative intensity of the spots is not an accurate indication of the amounts of the compounds present, since the extent of the reaction varies. B. The primary basis of the separation in TLC is polarity C. Rf is calculated by dividing the distance traveled by the solvent by the distance traveled by the solute

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter33: High-performance Liquid Chromatography

Section: Chapter Questions

Problem 33.15QAP

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Similar questions

a) Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) can be used as examples to explain difference between adsorption and partition. For each of these chromatographic techniques, identify: + the stationary and mobile phase + how the mobile phase moves b) How is the Rf value for a spot on a TLC plate calculated? What can the Rf value be used for? In order to achieve the best separation of several components of different polarity in a mixture spotted on a TLC plate, what guideline should one follow regarding the choice of a developing solvent? (i.e. polar, non-polar, etc.)
In reversed phase HPLC, how will the retention time of a component of a mixture vary with the polarity of its molecules? Explain your answer
Of Aspirin, ethanol, acetaminophen, ethyl acetate, hexane, and water which could go undetected during HPLC analysis, but could result in a lower than expected melting point, why are they not detected by HPLC analysis?
Which of the following is not a method for measuring reaction rates? A) total pressure B) thin layer chromatography C) isometric barometry D) spectrophotometry E) gas chromatography
TLC was used to compare the solubility of two compounds A and B in a solvent system (acetic acid, methanol, H2O). The distances that solvent has moved in the silica gel TLC was 12 cm. and for the compounds were 2 and 8 cm respectively. (a) Calculate the Rf values and which compound is more soluble and which one is more polar. (b) What are the factors affecting the Rf value
Is thin-layer chromatography a type of normal-phase chromatography or a type of reverse-phase chromatography? Define these two classifications.
1. What are the principles involved in the separation of substances in Thin Layer Chromatography? 2. Enumerate the advantages of TLC over the ordinary paper chromatography.
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Chemistry Briefly describe the differences between the scanning and SIM approaches with reference to your data. Discuss how and why your scanning (TIC) and SIM (mass chromatograms look different. Pay particular attention to selectivity of compounds detected and signal-to-noise. What are some advantages of SIM? What are some disadvantages?
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1. In thin layer chromatography (TLC), why do you need to use a pencil in marking the spots, origin, and solvent front and not a marker? 2. Why is it necessary to mark the solvent front immediately? 3. Why do you need to ensure that the loading spot is above the solvent level in paper chromatography? 4. Why do different compounds travel different distances on the piece of paper?
5. Would you expect that changing the solvent will change the Rf value of the specific solute? Why?6. Suggest simple reasons why the Ni2+ and Fe3+ ions have different Rf values?7. What forces causes the eluting solution to move the chromatographic support material?