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Need more buffer?

That's odd Ekstasis. Did you measure the pH of each solution? I ask, because when the pH of either carbonate or bicarbonate is 10.33, both HCO3- and CO2-- exist in equilibrium.

The pKa of CO3 2- is 10.33, which means
that at a pH of 10.33 both carbonate and bicarbonate are present in equal amounts.

Perhaps it was the quality of your baking soda? Or perhaps my calculation above was out? However, if the pH is above 10.33 (ideally 11) then there's no other explanation for your results as essentially both solutions are identical.

I'm not so sure you should use washing grade sodium carbonate, as the impurities magnesium and iron, while only present in small amounts, may interfere with some reactions. 99+% Na(CO3)2 can be obtained from chem suppliers at a relatively low cost.

Looking back over my old notes I see that it wasn't quite as fast a reaction with bicarb, but all things tested at all concentrations produced expected results.
 
^^ Hey Phase glad to hear your input. Sorry no I have not done a pH test of the solutions. I don't own any pH kit not even a crappy pool pH test kit. I have only done a very buget makup of these two solutions. I have not even used scales for these two solutions as I have given mine away. I have used different ammounts of Bi-carb even to the point where I beleive the solution is saturated and still crappy results when compared to original buffer or my own washing soda (sodium carbonate) make one.

Please if you like to try making up the bi-carb solution and the washing soda solution and see what happens in your testing I would be interested too at what you find out with the technicals. I can only tell you that I used Mckenzie's brand box of Bi-carb and for the washing soda solution (buffer) I used Lectric brand of dry looking powdered washing soda. I have also used the wet looking washing soda crystals (also from the supermarket) a few years ago with the same good results.

Again I can only repeat that with known samples of previously tested MDxx, the washing soda solution worked very well just like the original buffer with Simons. The Bi-carb solution worked but much slower and nowhere near as strong a reaction.
 
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