Sciencemadness Discussion Board

Calcium cations out of insoluble in water plant ash

Romix - 17-9-2024 at 17:59

Ok, here’s a question for you about the common elements of the periodic table.

I've removed Potassium from plant ash with water, not all of it, maybe some still remains, doesn’t matter...

Insoluble ash in water is dissolved in vinegar. After precipitation with Potassium Hydroxide, bringing the PH to very basic, a lot of Calcium is still in solution! Which then falls on the CO₃²⁻ anion with alkaline cations. Where does it fall from??? Why not drop all on alkaline hydroxides???? Like pure chalk is dropping on the CO₃²⁻, tested it.

[Edited on 18-9-2024 by Romix]

averageaussie - 17-9-2024 at 20:16

what is it here you are confused about?
the presence of calcium ions? carbonate ions?

Romix - 17-9-2024 at 20:24

Quote: Originally posted by averageaussie  
what is it here you are confused about?
the presence of calcium ions? carbonate ions?

Why lots of Calcium left in solution after PH becoming very basic, any precipitate stops forming and why all Ca not falling out with the rest of it?


[Edited on 18-9-2024 by Romix]

Romix - 17-9-2024 at 20:29

By lots I literally mean ounces in couple litres of vinegar.
Did it many times, on different kind of plant ash, happens every time.

DraconicAcid - 18-9-2024 at 06:32

Calcium hydroxide is relatively soluble. If you want to precipitate it, add carbonate.

Romix - 18-9-2024 at 06:43

Quote: Originally posted by DraconicAcid  
Calcium hydroxide is relatively soluble. If you want to precipitate it, add carbonate.

Are you sure Dear????
1.73 g/L won't make ounces of CaCO3!!!

DraconicAcid - 18-9-2024 at 14:36

I don't know what your first language is, but you don't address a stranger as "Dear" in any English-speaking country, unless you're flirting with them or trying to start a fight.

Romix - 18-9-2024 at 14:40

Quote: Originally posted by DraconicAcid  
I don't know what your first language is, but you don't address a stranger as "Dear" in any English-speaking country, unless you're flirting with them or trying to start a fight.

Not English, I'm not flirting and not starting a fight, showing respect I do that way. Don't care what you think!

averageaussie - 18-9-2024 at 15:37

Quote: Originally posted by Romix  

Not English, I'm not flirting and not starting a fight, showing respect I do that way. Don't care what you think!

Romix. you are on an english speaking board, so it is your best interest to follow customs in the english language, for the sake of your reputation.
in english speaking countries, dear has 2 purposes. it is either used to refer to someone you are in an intimate relationship with, i.e dating or married, or trying to insult. it is never used in an academic setting to refer to colleagues. you do not know these people personally, nor are you trying to start trouble, I understand that. but for your own sake, please use proper language to refer to people who are your peers.

I dont intend to be disrespectful in saying this, and I understand you use it as a sign of respect. but if you do respect these people, you will respect how they prefer to be referred to.

[Edited on 18-9-2024 by averageaussie]

Romix - 18-9-2024 at 15:44

Quote: Originally posted by averageaussie  
Quote: Originally posted by Romix  

Not English, I'm not flirting and not starting a fight, showing respect I do that way. Don't care what you think!

Romix. you are on an english speaking board, so it is your best interest to follow customs in the english language, for the sake of your reputation.
in english speaking countries, dear has 2 purposes. it is either used to refer to someone you are in an intimate relationship with, i.e dating or married, or trying to insult. it is never used in an academic setting to refer to colleagues. you do not know these people personally, nor are you trying to start trouble, I understand that. but for your own sake, please use proper language to refer to people who are your peers.

I dont intend to be disrespectful in saying this, and I understand you use it as a sign of respect. but if you do respect these people, you will respect how they prefer to be referred to.

[Edited on 18-9-2024 by averageaussie]

Ok!

bnull - 18-9-2024 at 17:09

I have spoken occasionally with Indians (from India) and as a rule they addressed me as Sir, Dear Sir, with such formality that made me feel as an aged wise man, rather than the obnoxious old fart that I am. It's cultural, respect for the elders etc.

Anyway. @Romix, correct me if I'm wrong. You mixed the ashes with water, filtered the suspension, then reacted the solids with vinegar. After that, you added potassium hydroxide to increase the pH and precipitate whatever it was that could be precipitated. Finally, you used an alkaline carbonate, sodium carbonate probably, and it was now that something more precipitated.

That's odd. It looks like calcium hydroxide but you say that there were always ounces (tens of grams) of it, no matter from what plant the ashes came. It is neither aluminum hydroxide nor silica because they wouldn't precipitate with carbonate in alkaline solution; there is plenty silica in ashes and only traces of aluminum. Magnesium hydroxide is practically insoluble. Barium hydroxide is quite soluble: about 86 g/L for the octahydrate; the problem is that there wouldn't be that much barium in a plant.

Do you have some sodium sulfate? If so, you can repeat the process, this time adding sodium sulfate instead of potassium hydroxide, so you can see if it really is calcium that is precipitating or something else.

averageaussie - 18-9-2024 at 17:36

Quote: Originally posted by bnull  
I have spoken occasionally with Indians (from India) and as a rule they addressed me as Sir, Dear Sir, with such formality that made me feel as an aged wise man, rather than the obnoxious old fart that I am. It's cultural, respect for the elders etc.


alright, didnt know it was part of their culture. thank you for clearing that up.

Romix - 19-9-2024 at 04:16

Quote: Originally posted by bnull  
I have spoken occasionally with Indians (from India) and as a rule they addressed me as Sir, Dear Sir, with such formality that made me feel as an aged wise man, rather than the obnoxious old fart that I am. It's cultural, respect for the elders etc.

Anyway. @Romix, correct me if I'm wrong. You mixed the ashes with water, filtered the suspension, then reacted the solids with vinegar. After that, you added potassium hydroxide to increase the pH and precipitate whatever it was that could be precipitated. Finally, you used an alkaline carbonate, sodium carbonate probably, and it was now that something more precipitated.

That's odd. It looks like calcium hydroxide but you say that there were always ounces (tens of grams) of it, no matter from what plant the ashes came. It is neither aluminum hydroxide nor silica because they wouldn't precipitate with carbonate in alkaline solution; there is plenty silica in ashes and only traces of aluminum. Magnesium hydroxide is practically insoluble. Barium hydroxide is quite soluble: about 86 g/L for the octahydrate; the problem is that there wouldn't be that much barium in a plant.

Do you have some sodium sulfate? If so, you can repeat the process, this time adding sodium sulfate instead of potassium hydroxide, so you can see if it really is calcium that is precipitating or something else.

Yes, correct, that's exactly what I did and done it lots of times on different batches of ash, ounces of chalk were precipitating on CO₃²⁻ every single time after all!!! Precipitate is definitely chalk!!!!! I've tested it in many ways like reacting it with HCl and doing flame tests, also it's sucking water exactly like CaCl2, very hygroscopic, sulphate anion test also, all tests are saying that it's chalk!!!!



[Edited on 19-9-2024 by Romix]

bnull - 19-9-2024 at 08:25

Hmm... How many ounces per pound of ash?

If you live about south of Birmingham (close to Bromyard or Northleach, or perhaps even Tidworth), the soil is heavy on calcium. It's chalk or limestone for tens of kilometers. If so, the plants are just taking up that much calcium, in quantities that seem excessive compared to plants from northern places.

Romix - 19-9-2024 at 09:15

Quote: Originally posted by bnull  
Hmm... How many ounces per pound of ash?

If you live about south of Birmingham (close to Bromyard or Northleach, or perhaps even Tidworth), the soil is heavy on calcium. It's chalk or limestone for tens of kilometers. If so, the plants are just taking up that much calcium, in quantities that seem excessive compared to plants from northern places.

In between 1 and 2. Would've weighed it, all already combined in one bag.
Can't tell about weight of the ash dissolved, but I do know quantity of solvent used, 2 liters of 10% vinegar used on every batch of ash.




[Edited on 19-9-2024 by Romix]

Romix - 19-9-2024 at 09:32

Yes, between 1 and 2 ounces. 
First batch I did yield 50 grams of hydroxides combined with carbonates. Remember weighing them!
I have a feeling that vinegar used doing first batch been diluted a little bit, less than 10%, lids on the bottles wasn't sealed. 
Second batch yielded much more chalk than first one did, maybe over 2 ounces.
I have photo of hydroxides and carbonates on scale somewhere here on the forum, take in mind that both were washed with plenty of water so like some of the precipitate got lost washing, if you understand? Also, leftover Carbon on filter could absorb good percentage. Let me find this photo...



[Edited on 19-9-2024 by Romix]

Romix - 19-9-2024 at 09:35

Yes! CaCO3 on the right!

ash.jpg - 90kB

[Edited on 19-9-2024 by Romix]

bnull - 19-9-2024 at 13:15

Wood ash can be up to 55% CaCO3. Your plant ash is about 12%, maybe 15% considering losses. At ~2 ounces per pound (~125 grams per kilogram), what you've got from the plant ash is perfectly reasonable.

Still, it is strange that the hydroxide didn't precipitate when you made the solution alkaline. The odds are very small that an additive in the vinegar somehow formed a complex with calcium. It would have to be one heck of an additive, and if so, I'm really impressed.

Romix - 19-9-2024 at 14:08

Quote: Originally posted by bnull  
Wood ash can be up to 55% CaCO3. Your plant ash is about 12%, maybe 15% considering losses. At ~2 ounces per pound (~125 grams per kilogram), what you've got from the plant ash is perfectly reasonable.

Still, it is strange that the hydroxide didn't precipitate when you made the solution alkaline. The odds are very small that an additive in the vinegar somehow formed a complex with calcium. It would have to be one heck of an additive, and if so, I'm really impressed.

That what I thought at first too. Tested vinegar and all reagents, no Ca in any of them... No additives in Vinegar, not apple vinegar, pure 10% Acetic acid mate.
I've tried doing all type of manipulations like changing PH from basic to acidic and vice versa then trying to drop on hydroxide again!



[Edited on 19-9-2024 by Romix]