Can Magnesium Bicarbonate Be Made With Magnesium Carbonate?

[Travis]

A little off topic, but since you mentioned calcium hydroxide, I have a question for you Travis. I've tried using calcium carbonate mixed with carbonated water to make calcium bicarbonate. I was able to have a reaction that indicates conversion to calcium bicarb, but the reaction is not able to be carried out fully. There seems to be an equilibrium where no calcium carbonate gets converted anymore to calcium bicarb. A lot of calcium carbonate solid powder settles at the bottom.

Since the use of magnesium hydroxide to make mag bicarbonate carries out fully, with no visible dregs left behind, would it be reasonable to expect the use of calcium hydroxide to be fully completed when mixed with carbonated water (with repeated refills of CO2 to carbonate water) to make calcium bicarbonate?

I'm making an experiment now where instead of just drinking magnesium bicarbonate water alone, I want to drink a mixture of magnesium bicarb and calcium bicarb water. I wanted to see if they go well together, such that the calcium would keep magnesium from having a laxative effect, and to find out an appropriate ratio that is most effective. Since calcium has a constipatory effect, it might be able to balance out the laxative effect of magnesium. If successful, it could allow me to increase magnesium intake with less chance of loose bowel movement.

Perhaps you try lowering the pH first and then add the CO₂/carbonate? I think a high pH would tend towards the preservation of Mg=O, Ca=O, Mg–(OH)₂, and Ca–(OH)₂ bonds in water. These species are more soluble in acid, and I'd imagine this is why:

[1] H⁺ + HO–Ca–OH ⟶ ⁺H₂O┈Ca–OH ⟶ H₂O + ⁺Ca–OH

[2] ⁺Ca–OH + H⁺ ⟶ ⁺Ca┈OH₂⁺ ⟶ Ca²⁺ + H₂O​

With the right amount of acid, I think you could hydrolyze all covalent hydroxide bonds . . . perhaps making the subsequent carbonate addition more available for new Ca²⁺ ionic bonds.

[3] Ca²⁺ + 2HCO₃⁻ ⟶ Ca²⁺[HCO₃⁻]₂
​

And with an excess of carbonate, the pH could easily be raised back to 7.0!

 

[yerrag]

. . . perhaps making the subsequent carbonate addition more available for new Ca²⁺ ionic bonds.

[3] Ca²⁺ + 2HCO₃⁻ ⟶ Ca²⁺[HCO₃⁻]₂
​

And with an excess of carbonate, the pH could easily be raised back to 7.0!

Sorry, I'm not following here. I don't see any carbonate species in the reaction.

However, I put about 10 ml of vinegar into 1400 ml of water, added 20g of magnesium hydroxide, in a 2 liter Coke PET bottle. I then pressurized with CO2 at 30 psi. Then I shook the bottle continuously until it collapsed to a point where it stopped collapsing, the result of CO2 being used to form magnesium bicarbonate and leaving less gas). I repeated this process 14x until very little reactant in magnesium hydroxide was left.

There was much less unreacted magnesium hydroxide left as compared to when I didn't use any vinegar. In the no-vinegar added control, it took only 8 reps to reach the point where magnesium hydroxide is no longer reacting, as compared to 14 with the vinegar added.

I'll try the same thing with magnesium carbonate and see where it takes me. Ditto with calcium carbonate.

 

[Travis]

Sorry, I'm not following here. I don't see any carbonate species in the reaction.

However, I put about 10 ml of vinegar into 1400 ml of water, added 20g of magnesium hydroxide, in a 2 liter Coke PET bottle. I then pressurized with CO2 at 30 psi. Then I shook the bottle continuously until it collapsed to a point where it stopped collapsing, the result of CO2 being used to form magnesium bicarbonate and leaving less gas). I repeated this process 14x until very little reactant in magnesium hydroxide was left.

There was much less unreacted magnesium hydroxide left as compared to when I didn't use any vinegar. In the no-vinegar added control, it took only 8 reps to reach the point where magnesium hydroxide is no longer reacting, as compared to 14 with the vinegar added.

I'll try the same thing with magnesium carbonate and see where it takes me. Ditto with calcium carbonate.

I was simply thinking that you could: (1) hydrolyze-off the hydroxyl groups using an acid (H⁺), and then (2) add carbonate to form the ionic magnesium (bi)carbonate while concomitantly increasing pH. A little bit of residual (deprotonated) acetate of course would be present, but this is harmless and can even be considered beneficial.

But actually cycling this process would of course protonate the carbonate species, and not necessarily additional unreacted magnesium hydroxide.

 

[Such_Saturation]

I think magnesium hydroxide in sparkling water left overnight gives magnesium bicarbonate. Very refreshing drink and there’s some threads in the forum from some time back.

 

[meatbag]

Actually, magnesium oxide turns into magnesium hydroxide when mixed with water. And the magnesium hydroxide reacts with CO2 in carbonated water to form magnesium bicarbonate. I've made magnesium bicarbonate using both methods. Using USP-grade magnesium hydroxide, and technical grade magnesium oxide. The magnesium oxide, though, wasn't fully reacted, and some solids remain. I just wasn't sure if it was because magnesium oxide is in itself less soluble, or whether it was a technical grade I used (wan't using the technical grade for myself, but for my fishpond - to increase its magnesium content).

Did the mag carbonate solid ever get dissolved or reacted to leave no trace of the solid in the sparkling water? I haven't tried it but was thinking of doing so to see if it could be used as a reactant to make magnesium bicarb, just as I was successful using both magnesium hydroxide and magnesium oxide as reactants.

It turns out that the main use of magnesium carbonate is to make magnesium oxide. I guess that would probably mean that magnesium carbonate isn't that soluble.

Yeah it wasn't so great, there was some stuff not dissolved. I'd use the bicarb from hydoxide if I was gonna make something as it seems to be easier and there's already a good formula worked out. Or try to work out the right amount of mag carbonate, it should make some magnesium bicarb

 

[yerrag]

have a lot of gym chalk sitting around

2 Magnesium Carbonate + 2 Calcium Glugonate + 7 Acetic Acid = 2 Magnesium Bicarbonate + 2 Calcium Acetate

https://retail.vitalbulk.com/blog-vitalbulk/how-to-make-the-ideal-calmag-drink/

 

[yerrag]

From allreactions.com :

MgCO3(solid) + H2O + CO2 = boiling = Mg(HCO3)2(solution)