Neutralization
Neutralization is what happens when an acid and a base cancel each other out, creating something milder.
Vinegar is an acid and baking soda is a base. When you mix them in a bowl, they fizz and react until both are used up. What is left in the bowl is mostly water — milder than either ingredient on its own. The acid and the base canceled each other out.
Explaining neutralization by grade level
When you mix baking soda and vinegar, they fizz and bubble. That fizzing means the two things are changing each other. The sour vinegar and the powdery baking soda work against each other until neither one is strong anymore. What you have left is mostly water with some salt mixed in. The strong stuff became gentle.
Projects that explore neutralization
Neutralization means an acid and a base cancel each other out. Vinegar is the acid. Baking soda is the base. When you pour vinegar on baking soda, they neutralize each other and produce carbon dioxide bubbles. That gas is what makes the fizzing eruption.
Neutralization can also reverse the effect of an acid already in a mixture. In this experiment, vinegar separates casein protein from milk. After filtering the curds, you add baking soda to neutralize the leftover vinegar. Bubbles appear as the acid and base cancel each other out, leaving a sticky substance you can test as glue.
Not all substances cancel out the same amount of acid. You dissolve the recommended dose of four antacid brands — Milk of Magnesia, Gaviscon, Tums, and Tagamet — in separate beakers of water. Using a burette, you add hydrochloric acid drop by drop to each solution, stirring and checking the pH after every drop until it reaches 7.0 (neutral). The brand that requires the most acid to reach neutral has the strongest buffering power. The results show a wide range: one brand neutralized nearly three times as much acid as another.