What is the equivalence point in an acid-base titration? I'm supposed to do a virtual lab online and it tells you to find the equivalence point, but I don't know if that means when the pH is 7 or when the indicator changes colors.

The equivalence point of a titration occurs when the moles of one component you started with equals the moles of the titrant. This point may or may not be at pH=7.0. The END POINT occurs when the indicator changes color, where ever that may be. We try to match the end point and the equivalence point, obviously. The difference in the two is the titration error.

The equivalence point in an acid-base titration refers to the point at which stoichiometrically equivalent amounts of acid and base have reacted with each other. At this point, all the acid has been neutralized by the base or vice versa, resulting in the formation of a neutral salt and water.

Typically, the equivalence point is not exactly at pH 7, although it can be for certain specific acid-base reactions. The equivalence point can vary depending on the strength of the acid and base being titrated.

To find the equivalence point, you can use an indicator or a pH meter. An indicator is a substance that changes color in response to changes in pH. The choice of indicator depends on the pH range in which the equivalence point is expected to occur. For example, phenolphthalein is commonly used in acid-base titrations, as it changes color when the pH reaches around 8 to 9.

If you are using an indicator, you can visually identify the equivalence point by observing a color change. The color change occurs when the concentration of the acid or base being titrated is equal to the concentration of the titrant (the solution that is added to the acid or base to neutralize it).

Alternatively, you can use a pH meter to measure the pH of the solution during the titration. The equivalence point is reached when the pH of the solution remains constant or levels off after the addition of small amounts of the titrant.

In your virtual lab, you can look for a significant change in pH or a color change in the indicator to determine the equivalence point. It's also a good idea to refer to any specific instructions or hints provided in the lab to ensure accuracy.