Which of the following is true of the solubility product constant?
A. It is the product of the initial concentrations of the ions in a solution.
B. It is an equilibrium constant.
C. It is an equilibrium position.
D. Its value changes in the presence of a common ion.
I would go with B.
The correct answer is B. It is an equilibrium constant.
To understand why option B is true, let's first explain what the solubility product constant (Ksp) is. The solubility product constant is a measure of the extent to which a sparingly soluble salt dissociates into its ions in a solution at equilibrium. It is expressed as the product of the concentrations (or activities) of the ions raised to the power of their stoichiometric coefficients.
In the case of a salt with the general formula AB, the dissociation can be represented by the equation: AB ⇌ A+ + B-
The Ksp expression for this equilibrium is: Ksp = [A+][B-]
Since Ksp is an equilibrium constant, option B is correct. It describes the fact that the Ksp value remains constant at a given temperature for a specific solute, even if the concentrations of the ions change. This equilibrium constant is a characteristic property of a salt and indicates the solubility of the salt in a particular solvent.
The correct answer is B. It is an equilibrium constant.
The solubility product constant (Ksp) is a constant value that describes the equilibrium between a solid substance and its dissolved ions in a solution. It is the product of the concentrations of the ions raised to the power of their respective stoichiometric coefficients in the balanced chemical equation for the dissolution of the solid substance. The Ksp value remains constant at a given temperature and does not depend on the initial concentrations of the ions or the presence of a common ion. Therefore, option A is incorrect. The Ksp value provides information about the position of the equilibrium between the solid and the ions in solution, but it is not an equilibrium position itself. Hence, option C is incorrect. However, the Ksp value does change in the presence of a common ion, as it is influenced by the concentration of the ions in solution. Therefore, option D is correct.