Term: ionic strength, \(I\)
https://doi.org/10.1351/goldbook.I03180

Definition:
On a molality basis, \[I_{m}=\frac{1}{2}\ \sum m_{\text{B}}\ z_{\text{B}}^{2}\] where the sum goes over all the ions B. z B is the charge number of ion B. The ionic strength on a concentration basis is defined analogously \[I_{c}=\frac{1}{2}\ \sum c_{\text{B}}\ z_{\text{B}}^{2}\]

Related Terms:
1) charge number (http://doi.org/10.1351/goldbook.C00993).

Source: Green Book, 2nd ed., p. 50 (https://goldbook.iupac.org/files/pdf/green_book_2ed.pdf)

Citation: 'ionic strength, \(I\)' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.I03180

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