<p> Fall 2009 Name: Date:</p><p>Experiment 3.7A&B: Solvent and Polarity Effects in Thin-Layer Chromatography</p><p>Part A</p><p>Solvent Front trans-stilbene vanillin vanillyl alcohol Solvent (mm) (mm) Rf (mm) Rf (mm) Rf Hexane Ethyl acetate Acetone</p><p>Part B</p><p>Solvent System ______Solvent Front (mm)______trans-stilbene vanillin vanillyl alcohol Unknown(s)</p><p>(mm) Rf (mm) Rf (mm) Rf (mm) Rf value(s)</p><p>Unknown Number ______Unknown(s) ______</p><p>Rank the solvents and compounds in order of increasing polarities.</p><p>Rank Solvent Compound 1 (least polar)</p><p>2</p><p>3 (most polar) Fall 2009</p><p>A solvent that gives a high Rf value is said to have a high eluting ability. Rank the solvents in terms of eluting ability for each of the three compounds.</p><p>Rank Trans-stilbene Vanillin Vanillyl alcohol 1 (lowest) 2 3 (highest)</p><p>1. Do polar or non-polar solvents have greater eluting ability? Explain using observations above.</p><p>For each of the solvents used, rank the compounds (trans-stilbene, vanillin, vanillyl alcohol) in terms of </p><p> increasing elution rate (increasing Rf value).</p><p>Compound with Compound with Compound with Solvent lowest Rf intermediate Rf highest Rf Hexane Ethyl Acetate Acetone</p><p>2. Does the order of elution vary according to solvent polarity? Explain using observations above.</p><p>3. Do polar or non-polar analytes travel faster on silica gel? Explain using observations above.</p>