Linked from
The 19 pages that link to Ionic strength, each with the reason it gives.
Debye lengthRelated: It determines Debye length in dilute electrolyte solutions.
Chemical activityRelated: It helps estimate ionic activity coefficients in electrolyte solutions.
Solubility equilibriumRelated: It helps predict how dissolved ions deviate from ideal behavior.
Ion-exchange resinRelated: Solution ionic strength affects competition and resin selectivity.
pH indicatorRelated: Changes in ionic activity can shift indicator behavior from ideal predictions.