the energy of an electrostatic interaction between two charged atoms is dependent on the charges on the atoms, the distance between them, and the dielectric constant of the solvent. for example, the strength of a weak acid ( Ka , acid dissociation constant) depends on the strength of the electrostatic interaction between a negatively charged carboxylic acid group and a proton. the solvent dielectric constant has a large influence on the pKa for weak acids.