Question

Page 1 of 2 Exp. 3 Isolation of Caffeine from Instant Coffee: Extraction and Thin Layer Chromatography Please provide each question you answer. Pre-Lab 1. Explain what a "partition or distribution" coefficient is. Use a dra coefficient of 3. 2. Explain how centrifugation works and critical safety consideration 3. Explain what anhydrous calcium chloride is and what it does in thi 4. Explain how thin layer chromatography works, what an Rt signifie 5. If the above squares are the display on a Mettler Precision Scale that write in what 36 mgs looks like Post-Lab

Answer 1

1. Partition coefficient or distribution coefficient is the ratio of concentrations of a particular compound in two immiscible phases that is having a proper phase boundary like acetone and water etc.
2. In centrifugation the substance undergoing it rotated with a very high angular velocity this settles the denser materials away from the rotating axis and lighter materials are settled near the axis.
3. Anhydrous calcium chloride is used as a dehydrating agent so that the polarity of the solvent is accurate.
4. Thin Layer Chromatography works on the principle of cappillary rise and the mobile phase of the solvent moves up the plate/thin layer the spotted non volatile material also moves up along with the solvent to an extent depending upon the polarity of the solvent and the substance, moreover impurities are also separated depending upon their polarities. R_f signifies the retention of the spotted compound and is the ratio of the distance moved by the compound with respect to the distance moved by the solvent.