Final answer:
To derive the degree of dissociation, one should examine the reaction equilibrium by writing a dissolution equilibrium equation and solubility product expression for the ionic compound, then comparing the ion product with Ksp to determine the saturation status of the solution.
Step-by-step explanation:
We can derive the degree of dissociation by examining reaction equilibrium. In a chemical equilibrium involving a dissolved ionic compound, we use an equilibrium constant expression to represent the relationship between the concentrations of the ions in equilibrium with the undissolved solid. This constant is known as the solubility product (Ksp).
The process generally involves:
- Writing the balanced dissolution equilibrium equation for the ionic compound.
- Deriving the corresponding solubility product expression that mathematically represents the equilibrium situation.
- Converting the solubility (if given in mass per volume) to molar concentration.
- Determining the equilibrium concentrations of the ions from the balanced equation.
- Substituting these equilibrium ion concentrations into the solubility product expression to calculate the Ksp.
By comparing the calculated ion product (Q) of a solution with the Ksp, chemists can determine if a solution is unsaturated, saturated, or supersaturated, and predict whether a precipitate will form when two soluble salts are mixed. This comparison is a direct way to assess the degree of dissociation of an ionic compound in a solution.