A student needs to analyze a mixture containing an alcohol and a ketone by silica gel tlc. Consult the table of solvent polarities above and suggest a likely developing solvent. Explain
What table above?
To determine a suitable developing solvent for analyzing a mixture containing an alcohol and a ketone through silica gel TLC (Thin Layer Chromatography), one needs to consider the polarity of the solvent and solutes. Here's how you can approach finding a suitable developing solvent:
1. Look at the Table of Solvent Polarities: Consult the provided table of solvent polarities. This table ranks common solvents based on their relative polarities. Solvents towards the top of the list are more polar, while those towards the bottom are less polar.
2. Understand the Nature of the Compounds: Identify the characteristics of the alcohol and ketone in the mixture. Alcohols generally have polar functional groups (-OH), making them more polar than ketones. Ketones have a carbonyl functional group (C=O), which is relatively less polar compared to an alcohol.
3. Select a Developing Solvent: Considering the above information, you should aim to choose a developing solvent that is polar enough to separate the components of the mixture with good resolution. However, if the developing solvent is too polar, it might lead to poor separation and migration of the compounds.
Since an alcohol is more polar than a ketone, it's generally suggested to use a moderately polar solvent for TLC analysis of mixtures containing both compounds. Ethyl acetate, a moderately polar solvent, is often a suitable choice in this scenario.
However, it's important to note that the optimal developing solvent may vary depending on the specific alcohol and ketone present in the mixture. Therefore, it's recommended to perform some preliminary trials using different solvents or solvent mixtures to determine the ideal developing solvent for your particular mixture.
Remember, the most effective way to find the appropriate developing solvent is through experimental testing. TLC plates coated with silica gel can be utilized to test various solvents or solvent mixtures to observe the separation and migration of the alcohol and ketone bands on the plate.