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

A particular mixture was seperated into three components usin paper chromatography. the Rf value of dye A is 0.78, the Rf of dye B is 0.43 and the Rf of dye C is 0.19. What component of the mixture A,B,C is most attracted in the stationery phase and why?

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

Diethylamine (C4H₁1N) and n-butylamine (C4H₁1N) are colorless liquid amine compounds, suggest chromatographic conditions (stationary and mobile phases, pH of the sample) in order to separate these compounds using IEC. Predict the retention.

eaninesau Question 1 Describe in detail the process and mechanism by which thin layer chromatography functions in separating the compounds in a mixture.

3. (a) The following are the results from subjecting the lectin to SDS-PAGE: Band / Molecular Length 210 100 67 48 32 Lectin Weight (kDa) of Gel Migration Distance 7.2 1.8 2.5 3.2 3.9 4.7 3.5 (cm) Determine the molecular weight of the lectin. Show all workings.

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

From the study with UV-Vis spectroscopy, four samples of solutions with different known concentrations of atrazine were analyzed, using a 1 cm optical path cuvette at 220 nm. The analytical curve (calibration curve) with absorbance values ​​(y-axis) per atrazine concentration (x-axis) provided a straight line with the following parameters: linear coefficient = 0 and slope = 760. assumptions of the Lambert-Beer Law, evaluate the following statements: I. The molar absorptivity coefficient (E), under the described experimental conditions, cannot be determined. II. A sample of a solution containing atrazine with an absorbance of 0.2 will show a concentration of 2.6x10-4 mol/L. III. Atrazine concentrations could be determined due to absorption taking place in the visible region. IV. The change in absorbance as a function of the analyte concentration is directly related to the absorptivity coefficient of atrazine and the length of the optical path of the cuvette. It is correct only what is…

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