Final answer:
In an acid-base reaction, indicators or a pH meter can be used to determine if the reaction is completely neutralized.
Step-by-step explanation:
In an acid-base reaction, you can determine if it is completely neutralized using indicators or a pH meter. These tools help detect the point at which the reaction has reached neutrality. For example, in a titration, you would add a few drops of an indicator, such as phenolphthalein, to the acid solution. As you slowly add the base solution, you will observe a color change in the indicator from colorless to pink when the reaction is neutralized.