Saturation Vapour Pressure and Size of Condensation Nucleus

[摘要] In this paper convenient approximate expressions between saturation vapour and the size of a nucleus containing given amount of solute were derived. At first we assumed that saturation vapour pressure for plane surface of aqueous solution is given by where P is saturation vapour pressure of aqueous solution, Po that of pure water at the same temperature as the aqueous solution, θ mol concentration of solute, α, β, constants depending on the nature of solute. Then using (1) we derived approximate formulae of saturation vapour pressure for a condensation nucleus containing given amount of solute. They are as follows: where P' is saturation vapour pressure for the drop of solution of radius r, P0 that for plane surface of pure water at the same temperature as the drop, m the mass of solute in the drop, A, B, constants depending upon the nature of solute, r0 the radius of the drop when the solution is saturated with solute, r_??_, the radius of the final crystalline nucleus. Constants A, B were determined for NaCl-, MgCl2-, MgSO4-, K2SO4-, H2SO4-solution, and saturation vapour pressure versus drop size relations for several given amounts of solute were obtained for the above solution.

[学科分类] 大气科学