The result of a TLC experiment showed that a compound has an Rf value of 0.25 on a silica gel plate using 10% ethyl acetate in hexane as the mobile phase. Indicate if the Rf values of the compound would be higher or lower in each of the following solvents. Breifly explain your reasoning for full credit: (a) 100% hexane (b) 100% Toluene (c) 50:50 of hexane ethyl acetate (d ) 95:5 of ethyl acetate: methanol

Silica gel is very polar stationary phase. Therefore, more polar molecule sticks to silica gel on the TLC plate and has higherRf​value. True False

What is the order in which the following compounds would he eluted from an HPLC column containing a reversed -phase packing?(a) benzene, diethyl ether, n-hexane(b) acetone, dichloroethane, acetamide

2. Thin layer chromatography was performed to find the most effective mobile phase needed to separate a mixture containing three compounds (using silica gel as the stationary phase). TLC analyses were performed using five different mobile phases: (A) pure petroleum ether; (B) 25:75 ethyl acetate:petroleum ether; (c) 50:50 ethyl acetate:petroleum ether (D) 75:25 ethyl acetate:petroleum ether; and (E) pure ethyl acetate. Using the TLC results provided, indicate whether an effective separation was achieved for each of the five mobile phases. Be sure to provide a brief explanation for your answer and identify which mobile phase(s) could be used to offer an effective separation of this mixture using column chromatography. A D E

What is the relationship between elation volume and molecular weight of the elute?

Please give me correct solution.

Problem Solving 1. The following data were obtained by gas-liquid chromatography on a 40-cm packed column: Compound min W, min Air 1.9 Methylcyclohexane 10.0 0.76 Methylcyclohexene 10.9 0.82 Toluene 13.4 1.06 Calculate (a) the number of plates from each peak. (a) the average number of plates from each peak (b) the standard deviation for the average number of plates (c) the average plate height for the column. (d) the resolution for methylcyclohexene and methylcyclohexane.

Predict the order of elution for the silica gel adsorption TLC separation of the mixture containing aspirin, acetaminophen and caffeine using methylene chloride solvent. Explain.

Explain why TLC cannot be used for some volatile low molecular weight substances such as toluene.

If the stationary phase and the compound being tested are both polar, will the retention factor (Rf) likely be smaller or larger than if a nonpolar compound was tested? Why?