In the context of metal and halide compounds, how is Ksp typically expressed for MX?

The solubility product constant, denoted as Ksp, is an equilibrium expression used for sparingly soluble salts. For a metal halide compound represented as MX, where M is a metal cation and X is a halide anion, the dissociation of the compound in water can be described by the following equilibrium reaction:

[ MX \leftrightarrow M^+ + X^- ]

When one mole of MX dissolves in solution, it produces one mole of M^+ ions and one mole of X^- ions. Thus, if the solubility of the compound MX is represented as 'x' (the concentration of MX that dissolves), the concentrations of the ions at equilibrium would be:

• [M^+] = x
• [X^-] = x

The Ksp expression for this dissociation is constructed by taking the product of the concentrations of the ions, each raised to the power of its coefficient in the balanced equation:

[ Ksp = [M^+][X^-] = (x)(x) = x^2 ]

Hence, Ksp is expressed as the square of the solubility (x^2) in the case of a 1:1 salt like MX