Calculate Ksp from molar solubility.

Steps to Solve

1. Identify the dissociation of the salt

Determine how the salt dissociates into its ions in solution. For example, if we have a salt $AB$ that dissociates into $A^+$ and $B^-$. The dissociation can be represented as: $$ AB_{(s)} \rightleftharpoons A^+{(aq)} + B^-{(aq)} $$

2. Write the expression for Ksp

The solubility product constant (Ksp) is calculated using the concentrations of the ions at equilibrium. For the example salt $AB$, the Ksp expression would be: $$ Ksp = [A^+][B^-] $$ If the molar solubility of $AB$ is denoted as $s$, then: $$ Ksp = s \cdot s = s^2 $$

3. Substitute the molar solubility into the Ksp expression

If you have a specific value for the molar solubility (let’s say $s = 0.1 , mol/L$), substitute this value into the Ksp expression you derived: $$ Ksp = (0.1)^2 $$

4. Calculate the value of Ksp

Now perform the calculation. For the molar solubility of $s = 0.1 , mol/L$, we compute: $$ Ksp = 0.1^2 = 0.01 $$