The major difference between equivalence and endpoint is that endpoint is the point in the titration process which is indicated by the color change of the indicator, whereas equivalence point is that point where the chemical reaction of titration comes to an end.
A titration also called volumetric or titrimetric method; is used for determining the concentration of an unknown solute using a known concentration solution.
There are four different types of titrations, namely acid-base titration, redox titration, precipitation titration, and complexometric titration, depending on the chemical reaction that occurs between the titrant and the sample solution.
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A titrant is normally added from a burette to a known compound quantity until the reaction is complete. A visual indicator (buffer or pH solution) is commonly used to indicate the completion (endpoint or equivalence point) of the reaction. The titration formula may simply determine the concentration of the analyte since the concentration of titrant is already known.
To perform the process of estimate the concentration of a solute, a burette, and its stand, volumetric flask, conical flask, funnel, beaker, wash bottle, pipette, and appropriate chemicals are required.
What is the endpoint?
The endpoint in the titration process is the point at which a pH change causes the color of the indicator to change. This occurs when titrant and sample compound are mixed during the titration process. It comes either almost with the equivalence point or comes after the equivalence point and is considered an ideal point for completion of the titration.
At this point, the indicators will change color, and you will be able to get the readings to calculate the amount of the unknown concentration of the analyte.
For example, the acids and bases are normally colorless solutions. Hence, to determine the completion of an acid-base neutralization reaction, an indicator is used that can change the color of the reaction mixture with variations in pH. In acid-base titrations, phenolphthalein is the most commonly used indicator.
What is the equivalence point?
The equivalence point or stoichiometric point in the titration process is the point where the chemical reaction in the titration mixture ends. Equivalence point gives the point where the unknown concentration of analyte has completely reacted with the titrant. It is also known as a stoichiometric point that comes either almost with the endpoint or before the endpoint.
Changes in pH, temperature, conductivity, precipitation formation and other factors all contribute to reaching the equivalence point.
For example, in acid-base titrations, the equivalence point occurs when the mole of base equals the mole of acid, indicating that the solution contains only salt and water. When the acid is relatively weak and, the base is strong it produces salt and a weakly alkaline throughout the titration process resulting in a pH greater than 07.00.
To obtain the same equivalence point as the endpoint, it is significant that the pH of the indicator must match the pH at equivalence.
Difference between endpoint and equivalence point:
- The endpoint is a point where the indicator changes color to indicate that the titration is complete, while the equivalence point is a point where the titrant and analyte are chemically equivalent across samples.
- The endpoint does not always give the point where the compound has completely reacted with the titrant, while in the equivalence point the compound has completely reacted with the titrant.
- The endpoint is always indicated by the color change of the solution, while the equivalence point is not always indicated by the color change of the solution.
- The endpoint occurs after the equivalence point, but the equivalence point occurs before the endpoint.
- In the titration of weak acids, the endpoint appears just once, while the equivalence points can appear several times.
- At endpoint change in color indicates endpoint reached, while at equivalence point change in color indicates an approximation of equivalence point.
In analytical chemistry, titrations can be performed in a variety of reactions, including acid-base, redox, complexometric, and precipitation reactions. In which two important stages are reached during the process, known as the endpoint and equivalence point. Most people believe they are the same thing; however, they are not the same.
Because there is only a slight difference between an equivalent point and an endpoint, they can be considered the same for laboratory purposes.
Equivalence point vs Endpoint
Commonly asked questions on titration are as follows.
What comes first endpoint or equivalence point?
The equivalence point comes first before the endpoint, which indicates the reaction's conclusion. Endpoint and equivalence point both are important stages in titration since they indicate the reaction.
What are the examples of indicators used in different titrations?
Phenolphthalein, bromothymol blue, methyl violet, methyl red, methyl yellow, methyl orange, thymol blue, eriochrome black T, crystal violet, litmus, and starch indicator are some of the indicators used in different titration methods according to the reaction.
What methods are used to determine the equivalence point?
Color change, pH change, precipitate formation, conductivity change, and temperature change are all methods for determining the equivalence point.
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