Final answer:
To induce crystallization, one may cool a supersaturated solution to promote solute precipitation, introduce a seed crystal to stimulate nucleation, or mechanically agitate the solution. For certain compounds, it may also involve changing the solvent or using fractional crystallization to separate desired compounds from impurities.
Step-by-step explanation:
Inducing Crystallization in Solutions
There are several effective methods to induce crystallization if a compound fails to crystallize out of a solution. Firstly, manipulating the temperature can exploit the temperature dependence of solubility. Raising the temperature allows dissolving more solute, and upon cooling, the solute becomes less soluble promoting crystallization. If the cooling is gradual, the solution may become supersaturated.
The addition of a seed crystal can stimulate the crystallization process. Alternatively, mechanical agitation can also induce nucleation in the supersaturated solution. For compounds with a tendency to form oversaturated solutions, like sodium acetate trihydrate, crystallization may require the introduction of a seed crystal. Moreover, changing the solvent or using a technique known as fractional crystallization, where impurities remain dissolved at low temperatures while the desired compounds crystallize out can also be effective.