The correct answer is option 'D': Ionic product to be more than solubility product.

Explanation:

1. Understanding Solubility and Ionic Product:

Solubility refers to the maximum amount of a solute that can dissolve in a given amount of solvent at a specific temperature. It is usually expressed in terms of grams of solute per 100 grams of solvent.

Ionic product (Q) is the product of the concentrations (or activities) of ions in a solution, raised to the power of their stoichiometric coefficients in the balanced chemical equation.

2. Relationship between Ionic Product and Solubility Product:

The solubility product (Ksp) is a constant value that represents the equilibrium between a solid solute and its ions in a solution. It is the product of the concentrations (or activities) of the ions, each raised to the power of their stoichiometric coefficients.

Ionic product (Q) is a measure of the actual concentrations (or activities) of ions in a solution, regardless of whether the solution is at equilibrium or not. If Q is less than Ksp, the solution is unsaturated and more solute can dissolve. If Q is equal to Ksp, the solution is at equilibrium and the solution is saturated. If Q is greater than Ksp, the solution is supersaturated and precipitation will occur.

3. Precipitation and the Ionic Product:

When the ionic product (Q) exceeds the solubility product (Ksp), the solution becomes supersaturated with respect to the solute. This means that there are more ions in the solution than can be maintained in equilibrium with the solid solute.

As a result, the excess ions will start to come together and form a solid precipitate. This precipitation process is driven by the need to reduce the concentration of ions in the solution and restore equilibrium according to Le Chatelier's principle. The precipitate will continue to form until the ionic product (Q) equals the solubility product (Ksp) and the solution becomes saturated again.

Therefore, precipitation occurs when the ionic product (Q) is greater than the solubility product (Ksp). This is why the correct answer is option 'D': Ionic product to be more than solubility product.

Summary:

- Precipitation occurs when the ionic product (Q) exceeds the solubility product (Ksp).
- The ionic product is a measure of the actual concentrations (or activities) of ions in a solution.
- The solubility product is a constant value representing the equilibrium between a solid solute and its ions in a solution.
- When the solution becomes supersaturated, precipitation will occur to restore equilibrium.