[thesavikingthe]

I am trying to make potassium sodium tartrate from tartaric acid. I tried googling it but did not find a procedure online.
Can you tell me how to do it?
Thanks

[chenbeier]

How do you exchange from an acid the H⁺ to  Na⁺ or K⁺?

[thesavikingthe]

That is exactly what I'm asking

[chenbeier]

If you had HCl, what do you add to get NaCl?

[Babcock_Hall]

@OP, It is a forum rule (see red link) that you must first provide your attempt or give your thoughts before we can help you.

[thesavikingthe]

@OP, It is a forum rule (see red link) that you must first provide your attempt or give your thoughts before we can help you.

I have read the rules, and know that I should provide proof of my attempt, but since I haven't tried anything (besides googling it), I can't.

I don't know how to add two different ions on my acid. I could neutralise it with idk like Na₂CO₃ or NaHCO₃, but then I'd be left with disodium tartrate, right? That is the core problem for me. How do I get a salt with 2 different ions? Can I even do it?

[chenbeier]

Yes in this way you can start. But you have to prevent you get disodium tartrate. How do you would manage it?

[thesavikingthe]

Perhaps by neutralising the tartaric acid with a 50/50 solution of NaHCO₃ and KHCO₃. I dont have KHCO₃ . Even if I did have it how could I know that it wouldn't make potassium sodium tartrate and not disodium tartrate and dipotassium tartrate?
The only source of K ions I have is KNO₃, KCl and KMnO₄.

[chenbeier]

Ok. You can neutralize 1 mol NaHCO₃ with 1 mol tartratic acid. You get Monosodiumhydrogen tartrate. In a second step you need of course a potassium source, like KHCO₃, K₂CO₃ or KOH.
You can also mix disodium tartrate and dipotassium tartrate dissolved in water.

https://en.m.wikipedia.org/wiki/Potassium_sodium_tartrate

The potassium salt you described KNO₃, KCl or KMnO₄ would pollute your product. Permanganate additionally would oxidize the tartrate.

[thesavikingthe]

1) So I can mix disodium tartrate and dipotassium tartrate and they will exchange ions to make potassium sodium tartrate??

2) Can you confirm that if I react tartaric acid with NaHCO₃ it won't make disodium tartrate. If so how is that possible, why would't it neutralise both ends of the acid?

Btw this is really helpful

[Borek]

First things first: do you understand how the stoichiometry works?  How the result of the reaction can depend on amounts of reagents?

I don't know how to add two different ions on my acid. I could neutralise it with idk like Na₂CO₃ or NaHCO₃, but then I'd be left with disodium tartrate, right? That is the core problem for me. How do I get a salt with 2 different ions? Can I even do it?

In a general case there is no sure way of making a double salt. In most cases even using correct amounts of all reagents you will get a mixture of most thermodynamically stable salts. Rochelle salt is one of the special cases - it is more stable than the mixture of disodium tartrate and dipotassium tartrate.

[thesavikingthe]

Aaaaaaa. That I didn't know, that the potassium sodium tartrate is more stable than disodium tartrate and dipotassium tartrate. Thank you!

[chenbeier]

1) So I can mix disodium tartrate and dipotassium tartrate and they will exchange ions to make potassium sodium tartrate??

2) Can you confirm that if I react tartaric acid with NaHCO₃ it won't make disodium tartrate. If so how is that possible, why would't it neutralise both ends of the acid?

Btw this is really helpful

1 yes.
2 It is a matter of amount. 1 mol Sodiumhydrogencarbonate (0.5 mol sodiumcarbonate) + 1 mol Tartratic acid gives only the sodiumhydrogentartrate. If you take more sodiumhydrogencarbonate then of course you get full neutralisation.

[AWK]

You started a topic that, depending on what you want to achieve, can be easy or difficult. To obtain a solution with a stoichiometry of Rochelle salts it is enough to stoichiometrically mix sodium and potassium hydroxides with tartaric acid. By evaporating the solution to dryness you will get solid with a composition corresponding to the Rochelle salt, although it will practically not be there. The old American patent, which you can easily find on the Internet, says about the crystallization of this salt.