Homomolecular constant

We find that the Kelvin equation for the critical cluster size depends on the ratio of the product of the partial pressures of NH3 and HCl to the equilibrium constant Kp. The product pNH,f>HCi must exceed Kp for a critical cluster to exist. Physically this condition merely means that the product of the gas-phase partial pressures must exceed the equilibrium partial pressure product at that temperature for a solid phase to exist. It is equivalent to the condition that 5 > 1 for a critical cluster to exist for homogeneous-homomolecular nucleation. 

The values of homomolecular association constants of alcohols and acids are high, typieally in the range of 10 -1 O. Therefore eoncentration of the eomponent A is rather low, even at high content of solvate-inert component B, and may be neglected. 

The dependence of equilibrium constant for reaction [9.116] on e is similar in a concentration range from 0.5 to 1.0 molar fraction of aldehyde, if the degrees of homomolecular association for aldehydes and acetals are smaller than for alcohol and water. 

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