Question

Explain the term ‘solubility product’. How does it differ from ionic products?

Answer 1

Hint: Since it is written they are products. So they must be the product of their respective species they give in a solution phase after dissociation or ionization. The difference will be the type of reactant used. In one completely dissociated solid are taken and in another one sparingly soluble solid are taken.

Complete step by step answer:
The two terms solubility product and ionic product are completely different from each other. Let us understand them one by one.
First of all let us look at solubility products. It refers to the product of concentration of ions in their respective solution but the condition is that the solution must be saturated. A saturated solution is that solution in which no more solute can be added. In saturated solutions, dynamic equilibrium exists between the ions and the compound. Let us understand this by taking an example. When we dissolve ${\text{NaCl}}$ that is common salt in water, it keeps on dissolving. When you keep on adding ${\text{NaCl}}$, the concentration of ${\text{NaCl}}$ increases and ultimately a stage will come when no more ${\text{NaCl}}$ will be dissolved in the solution. This does not mean that the reaction or dissolution stops here. This means that as much as ${\text{NaCl}}$ is dissolving the same amount of ${\text{NaCl}}$ is getting precipitated again. This stage is known as dynamic equilibrium.
The solubility product is represented by ${{\text{K}}_{{\text{sp}}}}$.
Now, coming to ionic products. It is also the product of ions in the solution, but the solution need not to be saturated, it can be any solution. Hence, it is a much broader term than solubility products.
It is represented as ${{\text{K}}_{\text{i}}}$.

Note:
There is a term called supersaturated solution. We know heating causes expansion. So, when we heat a saturated solution, liquid also expands and hence, more solute can be dissolved in that extra space. The solution thus formed is called supersaturated solution. But when we cool the solution to room temperature the solution, the extra solute we added will precipitate out as now no extra space will be there.