Bonus: (10points) Consider-the following silica gel TLC plate of compounds-A,B,
ID: 692025 • Letter: B
Question
Bonus: (10points) Consider-the following silica gel TLC plate of compounds-A,B, and C Determine the Re values of compounds A, B, and C run on a silica gel TLC plate using hexanes as the solvent. Calculate your answer to the nearest 0.1 cm. You must show your work to receive credit. a) Information you will need to answer this question: · The distance between the origin and the solvent front: 3.0 cm. . The distance between the origin and the center of spot A: 1.0 am. · The distance between the origin and the center of spot B: 2.0 cm. The distance between the origin and the center of spot C: 1.5 cm. R. A b) Which compound, A, B, or C, is the most polar e) What would you expect to happen to the Rr values if you used ethyl acetate instead of hexanes as the eluting solvent? 12Explanation / Answer
a. Rf retention factor = distance of compound traveled / distance of solvent front
Rf for compound A = 1.0/3.0 = 0.34
Rf for compound B = 2.0/3.0 = 0.66
Rf for compound C = 1.5/3.0 = 0.5
b.
Compound A is more polar, always least traveled compound is more polar, because it will bind more tightly with silica gel
c.
Since ethyl acetate itself is more polar solvent all the three compound A, B and C will reach solvent front. Therefore Rf for all the compound will be Rf = 3/3 = 1