Equivalents
| Formula / Notation | Equiv. wt = M/n; n = H⁺, OH⁻, or e⁻ per formula unit |
|---|---|
| Also Known As | Equivalent weight, gram equivalent, normality (related), mEq, chemical equivalent |
What is Equivalents?
A unit expressing the reacting capacity of a substance. One equivalent of an acid contains one mole of H⁺ ions; one equivalent of a base contains one mole of OH⁻ ions. Equivalent weight = molar mass divided by the number of equivalents per mole.
Formula & Notation
Other Names / Synonyms: Equivalent weight, gram equivalent, normality (related), mEq, chemical equivalent
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
A unit expressing the reacting capacity of a substance. One equivalent of an acid contains one mole of H⁺ ions; one equivalent of a base contains one mole of OH⁻ ions. Equivalent weight = molar mass divided by the number of equivalents per mole.
Equivalents are used in acid-base titrations (defining normality of acid/base solutions), redox titrations (electron-equivalents), and some clinical analyses (mEq/L for electrolyte concentrations in blood: e.g., Na⁺ 135-145 mEq/L). Ion exchange capacity of resins is expressed in meq/g.
No direct safety concern for the concept. Calculating in equivalents rather than moles can lead to errors if the number of reactive groups (n) is misidentified. Double-check n values for polyprotic acids, polyvalent metal ions, and multi-electron redox changes.
The formula or notation for Equivalents is: Equiv. wt = M/n; n = H⁺, OH⁻, or e⁻ per formula unit