Question

can u help me with 1,2,3?

1. (2 pts - 1 pt for correct traveling order, 1 pt for explanation) Based on the skeletal structures of biphenyl, benzhydrol and benzophenone, for a given TLC eluent, which of the three compounds would you expect to travel further on the TLC plate, and why? Copy your prediction into the Introduction section of your lab notebook. 2. (1 pt -0.5 pts per spot) Calculate the retention factor (R1) for each of the spots on the example TLC plate below. eluent front 3. (2 pts) Does the polarity of the solvent system affect the relative Rr values of the components in a mixture being analyzed by TLC? In other words, will the use of a different solvent system change which component will migrate the most or least on the TLC plate? Explain why or why not.

Answer 1

piphenyl Benzohydrol. Benzophenone Among them, Biphenyl would travel faster than others duce to non-polar nature. The nature of stationary phase is poler, thas it binds the Polar component effectively and more polar components more are unable to run over TLC with sufficient speed. Polaning order Beneohydrol y Benzophenone 7 Bipneny More slowly a

2. Rf - Retention factor. Re distance frovelled by spot Tistance travelled by Solvent plant 30m f(1) - 1 con = 0.3135 3.2cth Tropeospot) 3.2002 Please note, I have taken arbitary values, Plese use a scale to measure the exact distance from lower line to spoto and solvent front and determine the exact values of Rf as I have done above. No, the solvent System Cannot alter the sequence of migration. Spot on top Cannot be cobsoned at lower 4 than others in any system. On Changing the solvent system Rf Changes but not for example Relative position is some the upper spet is on top in both Cases less polan Isolret More polan solvest

DATEUU The only difference one can observe is the Rf. Reason! - The polar Component bind efficiently onto the portar silica plate. Thus, a polan solvent allows it be dissolved more in solvent and bind les on silice plate. so o polar solvent system increases the solubility of compound & this allow them to move faster - but this is applicable for all spots (Compound The spots on top would abo be more soluble and would run even faster.