Nucleation in Precipitation Reactions

Before we begin a discussion of nucleation dturing a precipitation, we need to explain some of the intricacies of precipitation. We first start with two solutions, one containing the cation of interest and the other the anion. Both involve soluble substances like nitrates or chlorides for the cations and acids or sodium compounds (or the like) for the anions. When the two solutions are combined, a precipitate will form if its aqueous solubility, as defined by its solubility product, is less than either of the cation and/or anion solubilities. What this means is that if we use two soluble solutions and combine them, a precipitate will form if it is insoluble in the aqueous solution. There are many examples of precipitate formation. We need to define the effect of exactly how the precipitation should be carried out in terms of phosphor preparation. 

This effect has a decisive effect upon the precipitate obtained. 

---