A note on hydrations of ions

Solvation numbers of ions

“…A comparison of the solvation numbers in normal solutions of several salts determined by the parchment paper, saltingout, and diffusion methods has been made. 27 Assuming the chloride ion to have a solvation number of 4, the solvation numbers of the other ions have the following ranges: Na+, 8-17; K+, 5-14; Li+, 13-15.5; Br", -3-7.5, and I", 2-5. A comparison of the solvation of certain ions in 1 and 0.1 N solutions, respectively, show29 the values: Li+, 13-14-62; K+, 5-29.3; Cl", 4-26.6; I", 2-31.4. Solvation numbers of other ions have been measured using the parchment paper method;30•31 see Table I.…”

“…Absolute and conventional standard enthalpies of hydration for a cation, M, of valence z+ and for an anion, A, of valence z-are related by AH°u-+ = AH0mz+ -z+AH°b. * (27) AH°a'~= \•~+ z~AH°H+ (28) where the AH°'s are the conventional relative enthalpies and the AH0's are the absolute ionic enthalpies of the indicated species. Subtracting eq 28 from eq 27 yields for uni-univalent electrolytes /?…”

Solvation of Ions

“…A distinction has been made [27][28][29] between close or chemical hydration and the wider or physical hydration of ions. In chemical hydration complex, ions are considered to be formed.…”

“…A comparison of the solvation numbers in normal solutions of several salts determined by the parchment paper, salting-out, and diffusion methods has been made [27]. Assuming the chloride ion to have a solvation number of 4 the solvation numbers of the other ions have the following ranges: Na + , 8-17; K + , 5-14; Li + , 13-15.5; Br", 3-7.5, and I", 2-5.…”