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In some cases crystals do not form quickly and the solution remains supersaturated after cooling. This is because there is a thermodynamic barrier to the formation of a crystal in a liquid medium. Commonly this is overcome by adding a tiny crystal of the solute compound to the supersaturated solution, a process known as "seeding".
Solubility is temperature dependent. A solution containing a higher concentration of solute than the solubility is said to be supersaturated. A supersaturated solution may be induced to come to equilibrium by the addition of a "seed" which may be a tiny crystal of the solute, or a tiny solid particle, which initiates precipitation. [citation ...
This can be due to temperature changes, solvent evaporation, or by mixing solvents. Precipitation occurs more rapidly from a strongly supersaturated solution. The formation of a precipitate can be caused by a chemical reaction. When a barium chloride solution reacts with sulphuric acid, a white precipitate of barium sulphate is formed.
The result is a supersaturated solution, which is metastable and will rapidly exclude the excess solute if a suitable nucleation site appears. [ 4 ] The concept of solubility does not apply when there is an irreversible chemical reaction between the two substances, such as the reaction of calcium hydroxide with hydrochloric acid ; even though ...
Besides the well-known Pitzer-like equations, there is a simple and easy-to-use semi-empirical model, which is called the three-characteristic-parameter correlation (TCPC) model. It was first proposed by Lin et al. [22] It is a combination of the Pitzer long-range interaction and short-range solvation effect: ln γ = ln γ PDH + ln γ SV
A common practice is to cool the solutions by flash evaporation: when a liquid at a given T 0 temperature is transferred in a chamber at a pressure P 1 such that the liquid saturation temperature T 1 at P 1 is lower than T 0, the liquid will release heat according to the temperature difference and a quantity of solvent, whose total latent heat ...
The solution-friction model is derived on a pore-flow or viscous flow mechanism, but extends its applicability by incorporating the force balances on the species transporting through the membrane. This inclusion allows for a detailed understanding of the interdependent fluxes of water and salt, influenced by interactions between salt ions and ...
Mixture of polymers and solvent on a lattice. Flory–Huggins solution theory is a lattice model of the thermodynamics of polymer solutions which takes account of the great dissimilarity in molecular sizes in adapting the usual expression for the entropy of mixing.