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scilover89
Dec6-04, 12:44 AM
Recently, I mixed vinegar and soda water together in a plate, but the result was confusing. Since soda water contain sodium silicate and sodium ash, the result should be soluble, as sodium salts always dissolve in the water. However, in the experiment, I get some white pieces which can't dissolve in the water. What is it?

chem_tr
Dec6-04, 03:44 AM
Vinegar has some preservative compounds, I think the white pieces come from it. You wanted to do a neutralization, I suppose, I recommend that you do it with real chemicals to avoid side reactions (like those white pieces you saw in your experiment). You may be right about sodium salts' solubility, but consider that vinegar acid may produce silicate acid, which is poorly soluble in water.

pack_rat2
Dec6-04, 10:29 PM
Recently, I mixed vinegar and soda water together in a plate, but the result was confusing. Since soda water contain sodium silicate and sodium ash, the result should be soluble, as sodium salts always dissolve in the water. However, in the experiment, I get some white pieces which can't dissolve in the water. What is it?

Hmmm....by "soda water," what do you mean? Normally, that refers to a solution of CO2 in H2O, which is carbonic acid (a very weak acid). You add a little flavoring to make a carbonated beverage.

scilover89
Dec8-04, 01:21 AM
Hmmm....by "soda water," what do you mean? Normally, that refers to a solution of CO2 in H2O, which is carbonic acid (a very weak acid). You add a little flavoring to make a carbonated beverage.
I meant the solution of sodium carbonate and sodium silicate.

scilover89
Dec8-04, 01:24 AM
Vinegar has some preservative compounds, I think the white pieces come from it. You wanted to do a neutralization, I suppose, I recommend that you do it with real chemicals to avoid side reactions (like those white pieces you saw in your experiment). You may be right about sodium salts' solubility, but consider that vinegar acid may produce silicate acid, which is poorly soluble in water.
Yeah, the solution did contain sodium silicate as you predict earlier. So what could be the side effect chemical equation that produced silicate acid?
Anyway, thanks for your advice.

chem_tr
Dec8-04, 02:55 PM
It is clear I think; silicate acid is very sparingly soluble in water, so white precipitates will form. Maybe the ones you saw were just silicate acid, who knows? You may try treating this solution with a base, and report if these precipitates disappear. Then you can conclude that this is probably silicate acid.