E

Equivalence Point

n_acid × V_acid × M_acid = n_base × V_base × M_base
Quick Reference
Formula / Notationn_acid × V_acid × M_acid = n_base × V_base × M_base
Also Known AsStoichiometric point, neutral point (strong/strong only), equivalence point

What is Equivalence Point?

The point in a titration at which the moles of titrant added are stoichiometrically equal to the moles of the analyte being titrated. At the equivalence point, the reaction between titrant and analyte is theoretically complete. It differs from the endpoint, which is the observed color change.

Formula & Notation

n_acid × V_acid × M_acid = n_base × V_base × M_base

Other Names / Synonyms: Stoichiometric point, neutral point (strong/strong only), equivalence point

Properties & Characteristics

The equivalence point is the theoretical point in a titration at which chemically equivalent amounts of acid and base (or oxidant and reductant, or other reacting species) have been mixed. At the equivalence point, the reaction is stoichiometrically complete. For a strong acid/strong base titration, the equivalence point pH = 7.0 at 25°C; for weak acid/strong base, pH > 7; for strong acid/weak base, pH < 7. Determined by pH curve inflection point.

Uses & Applications

Equivalence points are used to determine the concentration of unknown solutions (titrimetric analysis), to determine pKa values (half-equivalence point method), in pharmaceutical analysis (content assay by titration), and in environmental chemistry (alkalinity, hardness determination).

Safety Information

At the equivalence point in an acid-base titration, the solution may be slightly acidic or basic (depending on whether a weak acid or base is involved). Neutralised solutions are generally less hazardous than the starting acid or base, but should still be disposed of properly.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Equivalence Point
Formula n_acid × V_acid × M_acid = n_base × V_base × M_base
Synonyms Stoichiometric point, neutral point (strong/strong only), equivalence point

Frequently Asked Questions

The point in a titration at which the moles of titrant added are stoichiometrically equal to the moles of the analyte being titrated. At the equivalence point, the reaction between titrant and analyte is theoretically complete. It differs from the endpoint, which is the observed color change.

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