Question

Post-Laboratory Questions Aspirin adnil tuleno Which compound turned out to be the most polar? The least polar? Do experimental results agree with your theoretical predictions? If not, why? 2. What would a chromatogram look like if a less polar developing solvent were used 3. Consider the following TLC plate of compounds A, B, and C developed in hexanes: solvent front starting line a) Determine the R values of compounds A, B, and C run on a silica gel TLC plate using hexanes as the solvent b) Which compound, A, B, or C, is the most polar? c) What would you expect to happen to the Rr values if you used acetone instead of hexanes as the eluting solvent?

Answer 1

Content: Aspirin: Acetylsalicylic acid Advil: Ibuprofen Tylmol: Acetaminophen OOH Но НО- Acetylsalicylic acid is the most polar and acetaminophen is the leas polar. Experimental results are not given, hence may not be possible to compare with above prediction. 2) The acetamionphen will have highest Rf value, whereas aspirin (Acetylsalicylic acid) will have least Rf value. 3) Please note that I am using on screen ruler and hence actual scale may be different, leading to differen Rf value. a) Solvent front = 5cm distance traveled by A = 1.2cm distance traveled by B = 1.0cm distance traveled by C= 1.5cm Rf of A = 1.2/5 = 0.24 Rf of B = 1/5 = 0.20 Rf of C = 1.5/5 = 0.30

b) Compund B is the most polar as it is not moving least. c) Acetone being more polar solvent the all three compunds would move fast with the solvent front. Thus overall all the Rf values would increase when acetone is used insted of hexane.