In analytical chemistry, we use titration to determine acids, bases, reductants, oxidants, metal ions, and a variety of other species. Throughout the process of titration a chemical reaction occurs. In this case, an analyte reacts with a titrant, which is a standard reagent filled in the burette.
As a reference material in titrimetric methods, we sometimes use a primary standard, which is a highly pure and stable solution. To findout the endpoint of the reaction, we use an indicator. However, this is not the point at which the chemical process ends. The equivalence point is the actual point.
What is an endpoint?
Endpoint refers to the point in the titration process where the color of the indicator changes. For example, when Eriochrome Black T (EBT) is used as an indication in complexometric titration, the color changes from wine red to blue at the endpoint.
What is an equivalence point?
The point in the titration process where the chemical reaction in the titration mixture ends is called the equivalence point. It is also known as a stoichiometric point in titration. pH change, color change, precipitation formation, temperature change, and conductivity change are all methods for establishing the equivalence point.
How does the equivalence point differ from the endpoint and which comes first during titration?
There are two important stages, known as the endpoint and equivalence point, that are reached during the process. In a titration, an equivalence point is a point where the added titrant is chemically equivalent to the sample analyte. The endpoint, on the other hand, is the point where the solution changes color.
The major difference between equivalence and endpoint is that the equivalency point is the point at which a chemical reaction comes to an end, whereas the endpoint is the point at which color changes. The equivalence point comes before the endpoint.
What is the difference between endpoint and stoichiometric point?
The equivalence point is the common name for the stoichiometric point, and the differences between them have already been described above.
Why does the endpoint occur after the equivalence point?
Because a chemical reaction always occurs before a color change, the endpoint appears soon after the chemical reaction reaches the equivalence point. The color changes at the point where the pH of the titration solution becomes basic. Therefore, the endpoint can be determined following the complete neutralization at the equivalence point.
What is the midpoint of titration?
It is a point at which precisely enough acid/base has been introduced to neutralize one-half of the acid/base that was initially present and occurs halfway to the equivalence point.
In other words, the point at which half of the analyte is neutralized by the added titrant is referred midpoint of titration.
Is it possible for the endpoint and equivalence point to be the same?
Although endpoints are often referred to as equivalence points, the two terms are not the same. Since the difference between an equivalent point and an endpoint is minimal, they can be regarded as identical for laboratory purposes.
What is the pH at the endpoint of a titration?
The pH at the endpoint of a titration involving a strong acid and a strong base will be 07.00, pH > 07.00 when a weak acid is titrated with a strong base, and pH<7 when a weak base is titrated with a strong acid.
Is the endpoint always after the equivalence point?
The endpoint of the titration comes is either almost or after the equivalence point and the equivalence point of the titration comes either almost with the endpoint or before the endpoint.
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