Key Difference – Ionic Product vs Solubility Product
Both ionic product and solubility product express the same idea of the product of concentrations of ionic species in a solution. The key difference between ionic product and solubility product is that ionic product is the product of ions in either an unsaturated or saturated solution whereas solubility product is the product of ions in saturated solutions.
The solubility product is a form of the ionic product. The ionic product and solubility product differ from each other based on the type of solution considered.
CONTENTS
1. Overview and Key Difference
2. What is Ionic Product
3. What is Solubility Product
4. Side by Side Comparison – Ionic Product vs Solubility Product in Tabular Form
5. Summary
What is Ionic Product?
The ionic product is the product of concentrations of ionic species in either a saturated or an unsaturated solution. When only the saturated solutions are considered, the ionic product is known as the solubility product. The term ionic product is applicable for all types of solutions.
What is Solubility Product?
Solubility product is the equilibrium constant for a chemical reaction in which a solid ionic compound dissolves to yield its ions in solution. The term solubility product is used for saturated solutions only. Solubility product is denoted by Ksp. Let us consider an example;
Ag+(aq) + Cl–(aq)→ AgCl(s)
If the solution is saturated from AgCl (silver chloride), there is an equilibrium between soluble ionic species and the AgCl precipitate. The solubility product of this solution can be given as below,
Ksp = [Ag+(aq)][Cl–(aq)]
For any given solution (saturated), the solubility product is the product of ionic species raised into their stoichiometric coefficient. For the above example, the stoichiometric coefficients for Ag+ and Cl– ions are 1. Hence, the concentrations of those ions are raised into 1.
The smaller the solubility product of a substance, then lower the solubility of that substance. That is because solubility product gives how many dissolved ionic species present in that solution. If the amount of ionic species is a little amount, it indicates that the substance is not well-dissolved in that solvent. Then the solubility product is also low value.
Figure 01: Dependence of Different Compounds in Water and the Effect of Temperature on their Solubility
A major factor affecting the solubility product of a substance is temperature. When the temperature of a solution is increased, the amount of solutes dissolved in that can be dissolved in that solution is increased; which means, the solubility of a solute is increased. This leads to the increase of solubility product. Therefore, substances have different solubility products at different temperatures.
What is the Difference Between Ionic Product and Solubility Product?
Ionic Product vs Solubility Product |
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| Ionic product is the product of concentrations of ionic species in either a saturated or an unsaturated solution. | Solubility product is the equilibrium constant for a chemical reaction in which a solid ionic compound dissolves to yield its ions in solution. |
| Solution Type | |
| Ionic product is applied to both saturated and unsaturated solutions. | Solubility product is applied for saturated solutions only. |
Summary – Ionic Product vs Solubility Product
Ionic product and solubility product are two terms that express the same concept of the product of ionic species in a solution. The difference between ionic product and solubility product is that ionic product is the product of ions in either an unsaturated or saturated solution whereas solubility product is the product of ions in saturated solutions.
Reference:
1.Helmenstine, Anne Marie, Ph.D. “Solubility Product Definition.” ThoughtCo, Nov. 27, 2014. Available here
2.“Chemistry Dictionary.” Definition of solubility_product_ksp – Chemistry Dictionary. Available here
Image Courtesy:
1.’Temperature dependence solublity of solid in liquid water high temperature’ (CC BY 3.0) via Commons Wikimedia