Final answer:
The solubility-product expression for aluminum hydroxide (Al(OH)₃) is Ksp = [Al³⁺][OH⁻]³, representing the product of the concentrations of the ions produced when it dissolves in water.
Step-by-step explanation:
The solubility-product expression for aluminum hydroxide (Al(OH)₃) in its solid state is used to describe its solubility in water. This expression is derived from the dissolution equilibrium of aluminum hydroxide, which can be written as:
Al(OH)₃(s) → Al³⁺(aq) + 3OH⁻(aq)
Based on this equation, the solubility-product expression, or Ksp, is represented as:
Ksp = [Al³⁺][OH⁻]³
This corresponds to choice (a) in the question provided. It is important to note that the solid state of aluminum hydroxide ([Al(OH)₃]) does not appear in the expression since its concentration is constant and incorporated into the value of Ksp.