Accession Number : AD0679023

Title :   A GENERALIZED EQUATION FOR DROPLET GROWTH DUE TO THE SOLUTION EFFECT,

Corporate Author : ATMOSPHERIC SCIENCES RESEARCH OFFICE WHITE SANDS MISSILE RANGE N MEX

Personal Author(s) : Low,Richard D. H.

Report Date : SEP 1968

Pagination or Media Count : 26

Abstract : The fundamental parameter generally accepted in physical chemistry to account for the departure of a solution from ideality due to ionic dissociation and other causes is the mean ionic activity coefficient of the solute, rather than the van't Hoff factor commonly used in the literature and textbooks on cloud physics. It is directly related to many properties of a solution, one of which is the lowering of vapor pressure. The data on the activity coefficient of various electrolytes (or salts) are abundant and readily available; therefore it is fitting to express the equation for the solution effect on droplet growth in terms of this important parameter. A table is presented which gives the activity coefficients, the practical osmotic coefficients, and the van't Hoff factors of several salts in different concentrations. It is then shown that the generalized equation can be readily and exactly reduced to the expression derived by Byers for all concentrations and approximately to those given by Mason and Fletcher for very dilute solutions. (Author)

Descriptors :   (*WATER VAPOR, CONDENSATION), (*RAINDROPS, CONDENSATION), (*ARTIFICIAL PRECIPITATION, CONDENSATION), NUCLEATION, VAPOR PRESSURE, OSMOSIS, ELECTROLYTES, CLOUDS, DROPS, FOG, MATHEMATICAL ANALYSIS

Subject Categories : Meteorology
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE