Seperation of sodium and potassium carbonates

**JGM_14** · Aug27-07, 11:30 PM

I want to seperate sodium and potassium carbonate from the ashes of plants. My question is, Is sodium carbonate soluble in ethanol? I know that potassium carbonate is not so could i put the mixture into 200 proof ethanol and seperate the two?

**mgb_phys** · Aug27-07, 11:32 PM

Only a guess but sodium and postassium salts are going to have very similair solubility in anything.

**bomba923** · Aug28-07, 03:57 AM

Depending on the composition of your plant ashes, you may want to consider using crown ethers to separate your carbonates; specifically 15-crown-5 for your sodium and 18-crown-6 for the potassium carbonate.

Edit: If it does not interfere with your procedure, consider adding a strong base to deprotonate any groups (e.g., substituted ammoniums) that could otherwise inhibit the ethers' solvation of your cations.

**Lucas_SG** · Sep23-07, 07:45 AM

Basically, just remember, L S, B C L, S P A
All potassium,nitrate salts are soluble.. however, chlorides,carbonates and sulphates are an exception.For chlorides, all chlorides are soluble except lead chloride and silver chloride..all sulphates are soluble except barium sulphate,chloride sulphate and lead sulphate..for carbonates,sodium,potassium and ammonium carbonate is soluble while the rest are insoluble.. as as sodium and potassium are very reactive when reacted with water due to the reactive series of metals..u can seperate sodium and potassium with their solutions by titration, changing them into a oxide or hydroxide...

**bomba923** · Sep24-07, 01:46 PM

Originally Posted by Lucas_SG

Basically, just remember, L S, B C L, S P A
All potassium,nitrate salts are soluble.. however, chlorides,carbonates and sulphates are an exception.For chlorides, all chlorides are soluble except lead chloride and silver chloride..all sulphates are soluble except barium sulphate,chloride sulphate and lead sulphate..for carbonates,sodium,potassium and ammonium carbonate is soluble while the rest are insoluble.. as as sodium and potassium are very reactive when reacted with water due to the reactive series of metals.

As sodium and potassium salts have similar solubilities in aqueous solution, consider a solvent that can distinguish between either cation (try crown ethers)

Originally Posted by Lucas_SG

u can seperate sodium and potassium with their solutions by titration, changing them into a oxide or hydroxide...

This makes no sense.

**chemisttree** · Sep24-07, 05:46 PM

Solubility of potassium carbonate is 111 grams per 100 mL of water.
Solubility of sodium carbonate is 30.7 grams per 100 mL of water.
In a saturated solution, which would precipitate out first with careful drying and chilling?

Crown ethers are wicked expensive and toxic as *ell.

**Jeff Corkern** · Sep24-07, 10:43 PM

Originally Posted by JGM_14

I want to seperate sodium and potassium carbonate from the ashes of plants. My question is, Is sodium carbonate soluble in ethanol? I know that potassium carbonate is not so could i put the mixture into 200 proof ethanol and seperate the two?

I ain't real certain carbonates are there in the first place. Not if it's "ashes" as in ashes left over from a fire. Carbonate decomposes with heat to form carbon dioxide. It's why sodium bicarbonate smothers fire.

Somebody correct me if this is wrong.

Jeff Corkern
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**Cesium** · Sep25-07, 01:04 AM

Ya both carbonates are present in ashes. Na2CO3 predominates in sea plants and K2CO3 in land plants IIRC. This is an old school preparation of potash and is outlined in scores of old textbooks. Use Google books to help you- you'll get more info there than anyone on this forum can give!

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Backyard Chemistry

**Jeff Corkern** · Sep25-07, 06:19 PM

Originally Posted by Cesium

Ya both carbonates are present in ashes. Na2CO3 predominates in sea plants and K2CO3 in land plants IIRC. This is an old school preparation of potash and is outlined in scores of old textbooks. Use Google books to help you- you'll get more info there than anyone on this forum can give!

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Ah, so.

I stand corrected.

**chemisttree** · Sep26-07, 12:31 PM

Even if only the oxided or hydroxides were produced during burning, they absorb CO2 from the air and slowly convert to the carbonates.

**JGM_14** · Sep26-07, 06:29 PM

same with calcium oxide

**Jeff Corkern** · Sep28-07, 12:01 PM

I wondered how you could form carbonates in a fire . . .

Jeff Corkern
--------------------------------------------------------------------------------------
Consider the following as a statement of logic and rank it as "True" or "False."

"If people possess immortal souls, it should be possible to deduce this by logical analysis of their behavior."

www.theninepointfivetheses.blogspot.com
--------------------------------------------------------------------------------------

**JGM_14** · Oct6-07, 03:09 PM

how about a reaction with an acid then seperation