Questions 1 How would the following affect purification by c

Questions 1. How would the following affect purification by colunn chromatography (improve the separation, decrease the separation, or have no effect)? Why? a. You use a solvent which gives a TLC Rf of 0.55 for the compound you want b. You add the silica dry to the column instead of as a slurry c. Compound is put on as a dilute solution rather than as a concentrated solution. d. You drop the pipette into the top of the column. e. You load the compounds onto the column then take a 30 minute break. You collect fractions equal (in mL) to the amount of silica you used (in grams). g. When you analyze the fractions by TLC, you spot each one onlv once to the nlate

Solution

a) mixture may come instead of pure compound. solvent system first to be used should give a Rf Around 0.3. There is no hard and fast rule. Its from my experiences.

b) column will be dried as well as air bubbles will be there in the column.

c) there will be a good separation. but, compound you will be much less as some amount of compound will always be stuck in the column.

e) It is not done normally. you may collect at any proportions

f)

d) colum will be disturbed. anf hence uniformity in compund movement may be lost.

d) compound may get stuck. and either it will move very very slowly or you may lost a larg amount of compound.

f) its always useful. we will be able to monitor the producd properly.