If the solvent pool in a TLC developing jar is too deep, it can cause the sample spots to become diffused or spread out. This can lead to poor resolution and overlapping of the compounds being separated on the TLC plate. It may also make it difficult to accurately analyze and interpret the results.
If a solvent were to be saved, distillation would be the separation technique of choice. Distillation involves heating the mixture to separate components based on their different boiling points, allowing the solvent to be collected and reused.
If a substance is dissolved in a solvent, distillation allows recovery of both the solvent and the solute.
Developing the chromatogram too long can cause the solvent front to move off the edge of the paper, making it impossible to accurately measure Rf values. This error can lead to inaccurate identification of compounds as their Rf values will not be correctly calculated.
Ammonia would be the solute and water would be the solvent.
The solute would be iodine, and the solvent would be tincture
If a substance is dissolved in a solvent, distillation allows recovery of both the solvent and the solute.
You can use a technique called distillation to separate the solvent from a solution. Distillation involves heating the solution to evaporate the solvent, then condensing the vapor back into a liquid form to collect the pure solvent.
If a solvent were to be saved, distillation would be the separation technique of choice. Distillation involves heating the mixture to separate components based on their different boiling points, allowing the solvent to be collected and reused.
If a solvent were to be saved, the separation technique most likely used would be evaporation. This method involves heating the solution to turn the solvent into vapor, leaving behind the solute. It is effective for separating a solvent from a solute when the goal is to recover the solvent for reuse. Additionally, distillation could also be employed if the solvent and solute have significantly different boiling points.
In choosing solvent i would consider the following factors: What are the solutes? - are they polar or nonpolar how should they be dissolved What is the next step? - E.G. Do you need to distil or heat, then boiling point would be important. Is the solvent inert? Obviously side reactions are bad so choose a solvent which will not react. Good solvents are ethyl ether or ethyl alcohol.
If a solvent were saved and the goal is to separate components from a mixture while retaining the solvent, distillation would likely be the preferred separation technique. This method involves heating the mixture to vaporize the solvent, then cooling the vapor to condense it back into liquid form, effectively separating it from other components based on differences in boiling points. This technique is efficient for recovering solvents and purifying volatile substances.
If the solvent level in the developing jar is deeper than the origin (spotting line) of the TLC plate, the solvent will dissolve the compounds into the solvent reservoir instead of allowing them to move up the plate by capillary action. Thus, you will not see spots after the plate is developed. These photos show how the yellow compound is running into the solvent when lifted from the developing jar.
If the original spots were below the level of developing solvent then the components of the spotted sample would dissolve into the solvent and no spots would be seen upon analysis because all of the sample is dissolved in the developing solvent. hope this helps. good luck in o. chem!
You would recrystallize a solid from a solvent pair because if only one solvent was used, then it might be hard to dissolve the solute. In a solvent pair, one solvent would probably be better at dissolving the solute.
By placing the spot above the level of the solvent in the beaker, you slow the flow of solvent which results in improved separation of the components in the spot. If you placed it below the level of the solvent in the beaker, the solvent would just flow at a much faster rate and instead of separating the components in the spot, they would simply be washed away.
If a substance is dissolved in a solvent, distillation allows recovery of both the solvent and the solute.
The solute would be iodine, and the solvent would be tincture