Distribution of alkaline metal ions with respect to hydration power in aqueous solutions

A hypothesis on the binomial distribution of ions with respect to solvation has been advanced and tested by the mass spectrometric method of field evaporation of ions out of solution for ions of alkaline metals in aqueous solutions. The experimental distributions are described well by the binomial (p1 + q1)k1 where p1 is the probability of potential well occupation by a water molecule, q1 = 1 − p1 and k1 is the capacity of the first hydration shell. Values of p1, k1 and h (h is the number of water molecules in ions clusters corresponding to the maximum of the distribution; it is treated as the hydration number of the ion) are p1 /2~ 0.45, k1 /2~ 13, h = 5 (Li+); p1 = 0.32, k1 = 12, h = 4 (Na+); p1 = 0.35, k1 = 9, h = 3 (K+; p1 /2~ 0.29, k1 /2~ 8, h = 2 (Cs+).