Baking soda, a pure chemical called sodium bicarbonate, has the chemical formula:
NaHCO3
When dissolved in water baking soda separates into sodium (Na+) and bicarbonate ions (HCO3- ):
NaHCO3 ---> Na+(aq) + HCO3-(aq)
Vinegar, a weak (5%) solution of acetic acid in water, partially dissociates into hydrogen ( H+) and acetate ions (CH3COO-):
CH3COOH <--> H+(aq) + CH3COO-(aq)
The reaction between baking soda and vinegar is actually two reactions, an acid base reaction followed by a decomposition reaction.
When the two ingredients are mixed, hydrogen ions ( H+) from the vinegar react with the bicarbonate ions (HCO3- ) from the baking soda to form a new chemical calledcarbonic acid (H2CO3).
H+ + HCO3- ---> H2CO3
The carbonic acid thus formed then immediately decomposes into carbon dioxide gas (CO2)and water (H2O).
H2CO3 ---> H2O + CO2
It's this carbon dioxide gas that you see bubbling and foaming as soon as you mix baking soda and vinegar together.
Using the molecular structures of only the components involved, the chemical reaction can be written:
baking soda and vinegar reaction
The overall reaction however, is often written as follows:
NaHCO3 (aq) + CH3COOH (aq) ----> CO2 (g) + H2O (l) + CH3COONa (aq)
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