Bubble coalescence in some salt solutions can be inhibited if the salt concentration reaches a critical concentration C_(cr). There are three models available for C_(cr) in the literature, but they fail to predict C_(cr) correctly. The first two models employ the van der Waals attraction power laws to establish C_(cr) from the discriminant of quadratic or cubic polynomials. To improve the two models, the third model uses the same momentum balance equation of the previous models but different intermolecular force generated by water hydration with exponential decaying. The third prediction for C_(cr) requires the experimental input for film rupture thickness and is incomplete. We show further in this paper that the third model is incorrect. We propose a novel methodology for determining C_(cr) which resolves the mathematical uncertainties in modehng C_(cr) and can expplicitly predict it from any relevant intermolecular forces. The methodology is based on the discovery that C_(cr) occurs at the local maximum of the balance equation for the capillary pressure, disjoining pressure, and pressure of the Gibbs-Marangoni stress. The novel generic approach is successfully validated using nonhnear equations for comphcated disjoining pressure.
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