Final answer:
Bubbles are produced when acetic acid is added to sodium bicarbonate because the reaction releases carbon dioxide gas, following the chemical equation NaHCO3 + CH3COOH → NaCH3COO + H2O + CO2. This reaction results in a pH change of the solution towards being less acidic.
Step-by-step explanation:
Formation of a Gas in Chemical Reactions
When acetic acid is added to sodium bicarbonate, bubbles are produced because the reaction releases carbon dioxide gas. This type of reaction is an acid-base reaction where the acetic acid (the acid) reacts with sodium bicarbonate (the base) to form sodium acetate, water, and carbon dioxide. The chemical equation for this reaction is as follows:
NaHCO3 (s) + CH3COOH (aq) → NaCH3COO (aq) + H2O (l) + CO2 (g)
This reaction is similar to the reaction of sodium carbonate with hydrochloric acid, where carbon dioxide is also one of the products, demonstrating the typical outcome of such acid-carbonate/bicarbonate reactions.
Effect on pH
The pH of the solution after mixing vinegar (acetic acid) and baking soda (sodium bicarbonate) will become less acidic due to the formation of water and sodium acetate, both of which are less acidic than acetic acid. As a general principle, when a strong acid reacts with a strong base, the pH of the solution tends to be neutralized. However, in the case of acetic acid and sodium bicarbonate, since acetic acid is a weak acid and sodium bicarbonate is a weak base, the resulting solution's pH will be closer to neutral, but not completely neutral.