Molar Solubility
Definition and meaning of Molar Solubility in chemistry.
Molar solubility is the precise number of moles of a specific solute that can successfully dissolve in exactly one liter of a saturated solution.
In more detail
It fundamentally represents the absolute maximum concentration of a substance that can exist in a fully dissolved state under highly specific temperature and pressure conditions before solid precipitation inevitably begins. Molar solubility is mathematically directly related to the solubility product constant (Ksp) for sparingly soluble ionic compounds, and it provides a reliable way to quantitatively determine exactly how much of a solid will dissolve. The measured value can shift significantly due to external chemical factors such as the common ion effect or substantial changes in the solution's pH.
Key facts
| Field | Physical Chemistry |
|---|---|
| Units | Moles per liter (mol/L) |
| Related Constant | Solubility product constant (Ksp) |
The empirical molar solubility of silver chloride (AgCl) in pure water at 25 degrees Celsius is approximately 1.3 x 10^-5 moles per liter.
Frequently asked questions
How does the common ion effect specifically influence molar solubility?
Adding a common ion to the solution shifts the chemical equilibrium heavily toward the solid phase according to Le Chatelier's principle, thereby significantly decreasing the molar solubility of the compound.
What is the technical difference between general solubility and molar solubility?
Solubility can be widely expressed in various arbitrary units like grams per 100 mL, while molar solubility specifically strictly uses standard moles per liter.