Look for some books on separation techniques.

Find the main differences in properties between components such as melting point, boiling point, etc.

Look for some books on separation techniques.

Hi,

all the above mentioned separation techniques basically entail the phase transitions between different substances. For the record, yes each of the methods mentioned is quite broad and would require a lot of reading in the specific subject to fully understand them. Nevertheless:

a) sublimation: if You look at the phase transition diagrams, some substances do not have the liquid phase (at specific pressures), the easiest examples would be CO2 or I2, and as such they might be separated from materials which have phase transitions at other temperatures. For example You have mixture of substance A and B, and substance A sublimes at 140 oC, while substance B just starts melting at 140 oC -> hence the process of heating will separate both substances, because the phase transitions are different.

b) Evaporation: for different substances both melting and boiling points will be different, as such it is possible to separate them. The most straightforward example would be evaporation of a NaCl water solution -> by distilling off water the NaCl is separated from water to form a solid, this can be extrapolated to various substances. While evaporation mainly is used to remove solvents, re-distillation of an organic substance at lowered pressure definitely often yields good results as a purification method.

c) Decantation and filtration is basically the same method to separate a material which is soluable in a solvent from one which is not (decantation mostly is used for inorganic salts - the most frequent use is to decantate an organic solvent from Na2SO4 which was used to dry it after an extraction, while filtration can be used both in the aformentioned case as well as in cases where the density differential is not high at all). For example if You have an organic substance mixed with an inorganic base (lets say K2CO3) washing the mixture with Et2O or EtOAc (under the assumption the organic substance is soluable in the organic solvents) will remove the organic substance from the mixture while leaving the K2CO3 unaffected.

d) Precipitation and crystallization is basically the thing You do to form mixtures u can filtrate or decantate. The most strightforward approach would be: You have a mixture of A (90%) and B (10%), and You wish to remove the B from the aformentioned mixture -> generally for crystalline substances You will try to find a solvent in which both substances are somewhat soluable then heat it up to increase the solubility until everythings dissolved and then when the cooling starts the solution will become oversaturated, if the conditions and the chosen solvent is correct substance A will start to crystallize out of the solution as a crystalline material while B will still be dissolved in the solvent. Precipitation is basically the same with some minor differences ( an example would be if u take saturated NaCl water solution and add for example MeCN -> this will force fast precipitation of NaCl, because the formed water/MeCN mixture will not be able to dissolve all NaCl present).

Just to mention this again, if for example You might want to get familiar with crystallization several thousand pages of reading material awaits You, and even after that crystallization may be considered ''black magic'' especially in protein or glycoside chemistry.

Cheers,

Kaspars

I would suggest that you invest your own time to research and learn about each of the proposed techniques. Asking others to do your homework for you will not provide you with an opportunity to learn a key skill (How to research a question).

Sublimation is a technique to purify materials that have the property to get converted to gas directly from solid and vice-versa. This is good technique and involves no usage of solvents, etc Evaporation works well, when the material of interest is volatile and impurities are less volatile or vice-versa Decantation is a technique that works based on the density and solubility differences of the components of interest. Filtration is the best choice to separate solvents and liquids from solids of varying particle sizes, using the right filter media and size Precipitation works when an antisolvent is added to the solution of the component of interest in a solvent. Crystallisation is done in single or multiple solvent/media to decrease the solubility by polarity and temperature.