Equivalence point in relation with law of equivalence

Why is that we apply law of equivalence only at equivalence point during a titration. Isn't the law valid always? In the sense, cant we use law equivalence even before we reach the equivalence point?




We can, but properly.


* During titration, the molar amount of the used titrant is equivalent to the respective molar amount of the analyte **it has already reacted with**.
* At the equivalence point, the molar amount of the used titrant is equivalent to the respective total molar amount of the analyte **present in the sample**.
* After the equivalence point, the molar amount of the titrant **that reacted** is equivalent to the respective total molar amount of the analyte present in the sample.


So the amount of titrant that reacted is always equivalent to the amount of analyte that reacted. At the equivalence point, this is equal to the total amount of analyte and the amount of titrant added. At other stages, there will be excess of analyte or titrant, so the law is valid for the amount that reacted.


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