Vinegar, Baking Soda, and Salt
Name: David H.
Date: 2001 - 2002
When I mix apple vinegar and arm and hammer baking soda
I create a reaction (up to this point i understand what is happening), then
I go on to add family dollar store brand iodized salt this creates
another reaction. What happen to create this reaction? Is it creating
the reaction as if I where to stir it or did it create a completely
The first reaction vinegar (acetic acid) + baking soda (sodium hydrogen
carbonate) produces CO2 gas, which is what you expected. I can only
speculate what occurred when you added iodized salt (NaCl) since you did not
describe what you observed take place. My suspicion is you observed the
further evolution of some CO2 because the solubility of CO2 in a salt
solution is significantly less than its solubility in the vinegar/baking
Well, it's hard to say for sure what you are seeing because you didn't
describe the "reaction" that occurs. I am guessing that when you added salt
to the mixture, you saw bubbling, similar to the bubbling you saw when you
added baking soda to the vinegar.
Most likely, what happened is that you didn't wait long enough after adding
the baking soda to the vinegar. The salt doesn't do anything chemically
here. When baking soda is added to vinegar, it releases carbon dioxide gas.
This gas does not all immediately bubble away; some of it remains dissolved
in the solution and only slowly comes out. When the salt is added, it
entrains small bubbles of air with it that gives the dissolved carbon
dioxide additional surface to diffuse into. This speeds up the process of
coming out of solution.
If you saw something else, describe it and we'll try to see if we can figure
out what might have happened.
Richard E. Barrans Jr., Ph.D.
PG Research Foundation, Darien, Illinois
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Update: June 2012