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P2NP Recrystallization: Method for Purifying Substances
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- Опубликовано: 12 дек 2023
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🧪 In this video, we delve into the process of recrystallization, a widely employed method for purifying various substances. Specifically, we explore the recrystallization of phenyl-2-nitropropene (P2NP) as an effective means of purifying the substance. In chemistry, the purity of reagents directly influences the cleanliness and yield of the final product synthesized. Therefore, it is crucial to utilize reagents that are as pure as possible and have not expired.
Discover a treasure trove of specialized chemical knowledge by following the links provided at the end of the video. All media materials are available for download. On the forum, you'll find free consultations from highly qualified chemists, along with hundreds of verified original articles, methodologies, and experiments.
Placing it on ice is not a good idea. Just leave it to cool to room temp and then put on ice. Purer end product.
To add to this, stirring continuosly while crystallizing is necessary in the absolute majority of cases to get a purer end product. Large Crystals are a sign of decent purity, but they can actually entrap mother liquor, and make it harder to wash out impurities. There is a balance that must be achieved here, stirring to vigorously leads to too small crystals that catch a lot of mother liquor on the surface and need to be washed more, but since the surface area is large, you will lose more yield.
The correct balance is often only found experimentally, but "no stirring" is almost never the right answer, even though it seems to be done a lot. In industry, you stirr by default and only try not stirring in edge cases.
I could get purity of an industrial product up from 99,0 % to 99,95 % just by finding the right crystallization - and stirrer conditions without changing anything else, this absolutely matters. (Cooling down slowly was also part of the enhanced procedure, you're absolutely right about that.)
This channel is fantastic
1:39 so if you place water and ice in your ice bath, it can cool more evenly with less risk of thermal shock to the Borosilicate beaker. if you wait a bit for it to cool down and you then put some table salt on your ice, the ice will get even colder, but it will melt faster. but those cold areas do act as bit of a nice seed crystal so you could just place one ice cube above the water to make larger more pure crystals, if you don't want to drop a seed crystal in from the last batch. great video.
Спасибо за коментарий. Нам это известно, пусть знают и остальные.
Shouldn't you be using a round bottom flask suspended by a retort in the water bath? By simply placing one beaker into another the reaction flask is still in direct contact with the heat source making overheating far more likely
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