Suppose you are planning the separation of three compounds (A, B, and C) by column chromatography (CC) on silica gel.  You start by running several TLC’s in order to find the best solvent system for the separation. The results are summarized in the table below. Which solvent or solvents would be best for a separation of compound C  (from A and B) by column chromatography? Solvent Rf for A Rf for B Rf for C Hexane 0.04 0.30 0.04 Toluene 0.22 0.45 0.19 Dichloromethane 0.52 0.75 0.45 Ethyl acetate 0.80 0.80 0.76

Explain in details the basis and essence of High Performance Liquid Chromatography (HPLC) method of analysis.

In the diagram of TLC for column chromatography, What does light faded looking spots (less or less product, etc.)? Which fractions contain the product? concentrated 1 2 3 4 14 26 15 27 16 28 17 29 5 6 7 8 18 19 30 31 32 20 33 9 21 10 22 11 23 12 13 24 25 34 35 36 37 38

What is stationary phase used is liquid chromatography? What compounds does it bind best and why?

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4. What is the molar concentration of gold ion, Au*(aq), in a 1.00 M solution of Au(CN)₂ with no excess cyanide, CN- (aq)? (K₁ = 2.0 × 10³8 for Au(CN)₂)

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