How can a dilute acid dissociate more than a concentrated one? (Ostwald dilution law)

According to Ostwald's dilution law, the degree of dissociation of an electrolyte is inversely related to the concentration of it.


$$ \alpha = \sqrt{\frac{K\_a}{C}} $$


This means that a dilute acid can dissociate more than a concentrated one. How is it possible? Please explain the physical meaning of this.




A dilute acid has more solvent molecules to interact with than a concentrated acid, and thereby has more frequent collisions with the solvent. You can think of the dilute acid as "drowning" in the solvent.


A concentrated acid, by contrast, interacts more with other acid molecules, and therefore less with the solvent which dissolves it.


A concentrated acid will typically have more *total dissolved molecules* than a diluted acid simply because there are more of them, but it will have less *as a fraction of total number of acid molecules*; i.e. a weaker affinity for dissociation.


In short, $\alpha$ describes **affinity for dissociation**, not total dissociation. "Better", not "more".


Note that a higher $K\_a$ corresponds to a stronger acid, so it makes sense that stronger acids will have a higher affinity for dissociation.


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