This channel is fantastic

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.

@stefangadshijew1682

3 ай бұрын

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.)

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

bbgate

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.

@SafroleBlog

3 ай бұрын

Спасибо за коментарий. Нам это известно, пусть знают и остальные.