The process of rendering something pure, clean of foreign or undesired elements.
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1answer
41 views
What is the process for purifying KOH?
I'm partnered with a jewelry production company whose plating baths require KOH. We're located in Indonesia, where import fees are absurdly high, and reliable suppliers are rare. A local shop sells ...
4
votes
1answer
623 views
Acetic acid freezing distilation
How can acetic acid be distilled by freezing when its freezing point is above the freezing point of water.
Examples on the web show the water portion of the vinegar as ice and the acid as a liquid ...
5
votes
1answer
84 views
What happens during cleaning silverware?
I know two distinct recipes for cleaning silver:
Put them into a pot with some club soda and a piece of aluminium foil and pour over a hot water.
Gently clean silverware with a fine chalk powder ...
5
votes
1answer
184 views
Isolating salt from sea water using filters
Could a filter be used to isolating salt from sea water? Could we say that the water molecules are smaller than the molecules of salt dissolved in the water. I have no relation to chemistry or ...
4
votes
2answers
807 views
Copper Chloride: neutralizing and disposal
I plan on etching some PCBs with hydrochloric acid and hydrogen peroxide, which will therefore produce some kind of copper chloride (green color) which is highly toxic if released into the ...
3
votes
2answers
618 views
Difference between lab-grade and food-grade purity?
What is the difference in purity betwen lab-grade and food-grade when talking about potentially consumable compounds?
As an example let's take ascorbic acid powder: if it's marked as lab-grade, does ...
6
votes
0answers
59 views
Negative retention for chloride in hydrolysate filtration
I tried to fractionate proteins as a function of their size with an ultrafiltration membrane. I observed a higher concentration of chloride in my permeate than in my feed or retentate. The proteins do ...
5
votes
1answer
182 views
What is the behavior of a Zwitterion during ion exchange chromatography?
We're interested in purifying a protein that has an azide moiety using ion exchange chromatography. Due to its unique structure, the moiety is a Zwitterion with a novel chemical behavior. My question ...
9
votes
3answers
198 views
Silver, its bactericidal features and water
I often hear that water gets purified by being in a silver vessel, which sounds plausible because of bactericidal feature of silver. What doesn't sound plausible, though, is the way it's explained: ...
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1answer
224 views
Are there any general rules for choosing solvents for recrystallization?
Recrystallization is a nice way of purifying a product, but choosing a suitable solvent if you can't rely on the literature seems like a lot of trial-and-error.
Are there any general rules on which ...
6
votes
1answer
395 views
How does Polytetrafluoroethylene (Teflon) differ from Polyvinylidene fluoride (PVDF) as a protein binding membrane material?
PTFE and PVDF (durapore) are both used in protein binding filter membranes (Millipore specifically). Chemically speaking the two polymers differ quite significantly due to the additional fluorides and ...
