“…In the relations above, z designates the charge number of ions; m represents the ionic molalities in kg·mol –1 ; I = m NaCl + m RbCl indicates the ionic strength of the salts (total molality) NaCl and RbCl based on a molality scale; y refers to the ionic strength fraction ( y = y 2 = m RbCl / I ); and β (0) (kg·mol –1 ), β (1) (kg·mol –1 ), and C φ (kg 2 ·mol –2 ) designate the solute-specific interaction parameters of the Pitzer equation for single-salt electrolytes in the mixed solvent (alcohol + water), which are taken from the literature. , Parameters α and b are presumed to be invariable with quantities of 2.0 and 1.2 (kg 1/2 ·mol –1/2 ) correspondingly; in addition, θ NaRb (kg·mol –1 ) and ψ NaRbCl (kg 2 ·mol –2 ) are the two- and three-particle unknown mixture interaction parameters for a mixed-electrolyte system that can be determined based on a multiple linear regression method. A φ denotes the Debye–Hückel coefficient for the osmotic function of (alcohol + water) mixture and expressed as A φ = 1 3 false( 2 π N A ρ A ) 1 / 2 true( e 2 4 π ε 0 ε r k T ) 3 / 2 where N A , ε 0 , k , ρ A , T , and ε r signify Avogadro’s number, the vacuum permittivity constant, the Boltzmann constant, and the density, temperature, and relative permittivity of the mixed solvent, respectively.…”