Precipitation of an ionic compound will occur upon mixing of desired reagents if the initial ion product is: A) greater than the Ksp
B) equal to the pksp
C) equal to the Ksp
D) less than the Ksp

A) greater than the Ksp

Explanation:

Given a solid ionic compound AB, it dissociates in water into its ions, as follows:

AB(s) → A⁺(aq) + B⁻(aq)

At equilibrium, the product of the concentrations of the ions is constant, and it is called Ksp:

AB(s) ⇄ A⁺(aq) + B⁻(aq)

Ksp = [A⁺][B⁻] ⇒ (concentrations at equilibrium)

Upon mixing the reagents for the formation of AB, the compound will precipitate if the initial ion product (Q) is greater than the Ksp. If Q is equal to Ksp, the ions are at equilibrium with the solid compound AB, and if is it less than the Ksp, the ions are soluble and no solid AB is formed yet.

Q = [A⁺][B⁻] ⇒ (initial concentrations)

Q = Ksp ⇒ saturated solution (at equilibrium)

Q< Ksp ⇒ unsaturated solution (ions are soluble)

Q> Ksp ⇒ precipitation of solid compound.

Therefore, the correct option is A) greater than the Ksp