Question

(Experiment 12) PRELAB QUESTIONS Nane 1. Look at the attached picture. Rf is called the retention factor. Calculate c Distance the Sample Travelled the Rr for the spots in the picture below. Rf =- Distance the Solvent Front Travelled PAPER CHROMATOGRAPHY DBYJU'S Lid Solvent front Blue Paper 10 cm Purple Solvent front 8 cm 16 cm Red Solvent- Origin Color Rf Distance the Sample Travelled Distance the Solvent Front Travelled Red 10 cm 0.20 Purple 2cm 6cm I 8cm 10 cm N 0.60 0.80 Blue 10 cm w 2. Circle the color of the sample that has the strongest attraction for the solvent. RED PURPLE BLUE 3. Circle the color of the sample that has the strongest attraction for the paper. RED PURPLE BLUE 4. Assume the solvent is polar. Circle the color of the sample that is most polar. RED PURPLE BLUE 5. Assume the solvent is polar. Circle the color of the sample that is least polar (nonpolar). RED PURPLE BLUE

I need the answers or the explanation of the last 4.

Answer 1

2. blue because it goes with solvent 3. red because it has strongest attraction with silica 4. red because it has strongest attraction with silica which is polar in nature 5. blue Rf=distance moved by the compound or spot / distance moved by the solvent. The more polar a compound has the lower Rf value. Because Polar compound want to bond with polar silica, while non-polar compound will move fast with eleuent hence this non-polar has highest Rf value. The factors that influence the Rf of a compound on silica get TLC are following: 1. the TLC plate should be coated uniformity 2. sample should be dry on load time. 3. The sample should be same at every time (wt/ volume) 4. The chamber should be saturated by the mobile phase