Question

What is the affinity toward the silica gel surface for a compound with a high Re in a non-polar solvent? How would you expect the affinity to change in a more polar solvent? 5

Answer 1

Silica get is polar in nature while the compound din non polar solvent with high Rf has non polar because Polar compound want to bond with polar silica, while non-polar compound will move fast with eleuent Rf values range from 0 to 1 with 0 indicating that the solvent polarity is very low and 1 indicating that the solvent polarity is very high When we were switched from less polar to high polar solvent than Rf value will increases and move towards 1. 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 Rfof 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