Ostwald's Dilution Law
| Formula / Notation | Ka = α²c/(1-α) ≈ α²c for weak electrolyte; α = degree of dissociation |
|---|---|
| Also Known As | Ostwald dilution law, weak electrolyte dissociation law, α-c relationship |
What is Ostwald's Dilution Law?
A relationship derived from the equilibrium constant that describes how the degree of dissociation of a weak electrolyte varies with dilution. As concentration decreases, degree of dissociation increases. For weak acids: Ka = α²c/(1-α), where α is degree of dissociation and c is concentration.
Formula & Notation
Other Names / Synonyms: Ostwald dilution law, weak electrolyte dissociation law, α-c relationship
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
A relationship derived from the equilibrium constant that describes how the degree of dissociation of a weak electrolyte varies with dilution. As concentration decreases, degree of dissociation increases. For weak acids: Ka = α²c/(1-α), where α is degree of dissociation and c is concentration.
Ostwald's dilution law is used in: calculating the degree of dissociation and pH of weak acid/base solutions at various concentrations, understanding why weak electrolytes conduct electricity more freely at higher dilution (molar conductivity increases — Kohlrausch's law), and in designing buffer sy…
No direct safety concern. Ostwald's law explains why diluting a weak acid initially increases the fractional dissociation, which can cause unexpected pH values if miscalculated. In pharmaceutical quality control, dilution of weak acid drug solutions must account for this effect when setting pH speci…
The formula or notation for Ostwald's Dilution Law is: Ka = α²c/(1-α) ≈ α²c for weak electrolyte; α = degree of dissociation