NaOAc, KOAc and K2CO3.

Quote: Originally posted by Rainwater

Potassium carbonate wiki Potassium acetate wiki sodium acetate wiki Without spoon feeding you an answer, try reviewing the properties of each compound, specifically looking for something you can exploit to seperate them. Melting points Boiling points Solubility in different solvents It looks like seperation of the sodium acetate from the potassium compounds will be stright forward and simple.

Quote: Originally posted by Rainwater

Read this [Edited on 4-9-2023 by Rainwater]

Quote: Originally posted by Romix

Quote: Originally posted by Rainwater   Read this [Edited on 4-9-2023 by Rainwater] Thanks! But nothing there about mentioned salts.

Quote: Originally posted by RU_KLO

try looking here (solubility chart) https://en.wikipedia.org/wiki/Solubility_chart one possibility: Add Calcium chloride solution, dropwise until no more precipitate is formed. this will probably precipitate Calcium Carbonate from K2CO3. CaCl2 + K2CO3 -> CaCO3 (precipitates) + 2KCl filter to remove CaCO3 I don t know how will CaCl2 reacts with acetates, but acetates and Chlorides from K, Ca, Na are all soluble. then maybe adding HCl to convert everything to Chloride and use solubility tables to check which will precipitate first. from these, it seems that CaCl2 is the most soluble, so Na K chloride will precipitate first.

Quote: Originally posted by Romix

Quote: Originally posted by RU_KLO   try looking here (solubility chart) https://en.wikipedia.org/wiki/Solubility_chart one possibility: Add Calcium chloride solution, dropwise until no more precipitate is formed. this will probably precipitate Calcium Carbonate from K2CO3. CaCl2 + K2CO3 -> CaCO3 (precipitates) + 2KCl filter to remove CaCO3 I don t know how will CaCl2 reacts with acetates, but acetates and Chlorides from K, Ca, Na are all soluble. then maybe adding HCl to convert everything to Chloride and use solubility tables to check which will precipitate first. from these, it seems that CaCl2 is the most soluble, so Na K chloride will precipitate first. Thank you for the reaction, didn't knew about it, will try it out some day. But what's the point of this reaction? Adding another cation to the mix, that's all.

I will try to show you how I would think through the problem.
Im leaving out a bunch of stuff to keep this simple.
We will form a hypothesis and work through the numbers and process and try to predict a result.

You can read this in any text book, but if your like me, you need to hear the same think 3 different ways before it sticks.

To purify by recrystallization or percipitation

Start by listing the solubility of each component in a solution.
The sciencemadness wiki usually gives you the solubility for different common solvents.
The wiki trys to list at least 1 solvent that has a large change in temperature.
One solvent that has a small change in temperature
and one solvent that is insoluble

Water, alcohol, ether, acetone are commonly listed because of their ability to meet these requirements over a wide range of compounds

image source


1) The solvent with a large change in temperature, is great for purification via recrystallization or "selective precipitation"
2) Solvents with solubility that does not change much with temperature or are insoluble are good for "selective extraction"
3) Solvents which your target compound are insoluble are good for selective extraction and 4) selective precipitation

Example 1) extracting KCl from NaCl solution - recrystallization
NaCl has a solubility in water which is not changed much by temperature
KCl has a solubility in water which changes with temperature alot compared to NaCl

With this information, we can hypothesis that if you take a mixture of the 2 salts in an unknown ratio, and mix it with hot water, the resulting solution will contain a fixed amount of NaCl, and a variable amount of KCl.

Continuing the hypothesis, by changing the tempature of the solution, we can vary the amount of KCl in solution.

This is a simple overview. In truth, the amount of both salts in solution will change with temperature,
Between 0c and 100c we can expect the NaCl to change from 35g to 40g per 100ml of water
Between 0c and 100c we can expect the KCl to change from 25g to 55g per 100ml of water
These numbers are not exact, but close +/- 5g/100ml

If this hypothesis is true, we can expect a 100c saturated solution of these salts to cool to 0c and produce a percipitate that is enriched in KCl

If the data in the chart is accurate, we can expect 100ml of 100c saturated salt solution, to cool to 0c and produce a percipitate containing 5g NaCl and 30g of KCl

Now we have a known ratio of mixed salts.
we can hypothesis that if we add the correct amount of solvent to our sample, we can keep all the NaCl in solution and extract the most KCl possible.

Suppose that we made a large quantity of mixed salts that are at a ratio of 5g/NaCl and 30g/KCl or better stated as 1g/NaCl and 6g/KCl

We hypothesis 100ml of 100c solution will hold 55g of KCl
We hypothesis 100ml of 0c solution will hold 35g of NaCl

We want to disolive as much of our salt mixture as possible, without exceding the limit of NaCl that will remain in solution.

So now we have a simple logic problem
Easiest method for me to solve this problem is iteration
We want to see which limit is reached first.
If we add 7g of the mixed salt, that will give us 1g/NaCl and 6g/KCl, by repeating the iteration

Separating Compounds

Quote: Originally posted by Texium

Better yet though, just add acetic acid to convert any carbonate present to acetate without adding any additional cations or anions to worry about. Why has that not been suggested yet?

it has been already suggested, but the thread is so overblown that this is hard to see

[Edited on 6-9-2023 by teodor]

K2CO3 started falling out of the solution on slow evaporation on a lamp straight after the NaOAc porridge, massive and with visible crystal form, possible to capture.
Both salts are hygroscopic, meaning melting if stored or drying on fresh air by moisture in the air.






[Edited on 9-9-2023 by Romix]

Crystals grown in one night, pure 99% K2CO3, before I broke them down in to smaller pieces.
There's a similarity, sure!!



[Edited on 9-9-2023 by Romix]

Quote: Originally posted by Romix

What will happen to Acetates of Alkali metals if I add weak HCl to the salt? If anions will displace each other, what theoretically could happen. Or I'll just do next batch of plant ash in HCl instead of Vinegar. I can electrolyze Chlorides of Alkali metals, using Graphite electrodes specially made for electrolysis(used them for couple of days making NaOH and mixture of acids containing Chlorine, they not breaking and falling in to solution) but if they will, will it be safe to boil solution containing KClO3 with fallen in it Graphite, I know that it explodes with Carbon. How about Graphite and solved in water KClO3? Also I have long Titanium electrodes, may they be better? What glue would you recommend to me to stick the electrodes in a lid of a reactor where electrolysis will take place. Graphite electrodes could just be melted in to the lid, Titanium ones will need gluing because they are mesh. Also what polymer be best to for Chlorine outlet? [Edited on 26-11-2023 by Romix]

Quote: Originally posted by Rainwater

In the absence of a fuel, the salt will appear to boil and bubble. Decomposition will not deflagrate or explode. Keep it in a test tube or ceramic dish, away from most metals and other compounds. I dont think directly heating in a mapp flame would be any less safe that indirect heating. This is a dangerous procedure, but can be done safely. Sticking your finger into the molten salt will cause it to deflagrate, spilling some on yourself will have the same effect. Here is 3 grams of molten KClO3 and 3 grams of gummy worm. https://youtube.com/shorts/bI8ZZdBAEj0?si=fXfpolszCodA6w5x Stay safe