Ostwald dilution law
E1025756
The Ostwald dilution law is a principle in physical chemistry that relates the dissociation constant of a weak electrolyte to its degree of dissociation and concentration in solution.
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
equilibrium law
ⓘ
law in physical chemistry ⓘ |
| alsoKnownAs | Ostwald’s law of dilution NERFINISHED ⓘ |
| appliesTo |
weak acids
ⓘ
weak bases ⓘ weak electrolytes ⓘ |
| assumes |
ideal solution behavior
ⓘ
low concentration of electrolyte ⓘ |
| breaksDownAt |
high electrolyte concentration
ⓘ
strong interionic interactions ⓘ |
| category |
chemical equilibrium
ⓘ
electrolyte solutions ⓘ |
| concerns | relationship between conductivity and dissociation ⓘ |
| definesSymbol |
K as dissociation constant
ⓘ
c as analytical concentration of electrolyte ⓘ α as degree of dissociation ⓘ |
| describes | ionic equilibrium of weak electrolytes ⓘ |
| expressedAs | K = c·α² / (1 − α) ⓘ |
| field |
physical chemistry
ⓘ
solution chemistry ⓘ |
| hasApproximateForm | K ≈ c·α² for very weak electrolytes at low α ⓘ |
| hasMathematicalForm | K = [A⁻][H⁺] / [HA] for a weak acid HA ⓘ |
| helpsExplain | difference between strong and weak electrolytes ⓘ |
| historicalPeriod | late 19th century ⓘ |
| implies |
degree of dissociation increases with dilution
ⓘ
weak electrolyte becomes more dissociated at lower concentration ⓘ |
| languageOfOrigin | German ⓘ |
| namedAfter | Wilhelm Ostwald NERFINISHED ⓘ |
| relatedTo |
Arrhenius theory of electrolytic dissociation
NERFINISHED
ⓘ
Debye–Hückel theory NERFINISHED ⓘ law of mass action NERFINISHED ⓘ |
| relatesQuantity |
concentration of electrolyte
ⓘ
degree of dissociation ⓘ dissociation constant ⓘ |
| usedFor |
calculation of degree of dissociation
ⓘ
calculation of dissociation constant ⓘ estimation of strength of weak acids ⓘ estimation of strength of weak bases ⓘ |
| usedIn |
acid–base titration calculations for weak acids
ⓘ
determination of pKa of weak acids ⓘ determination of pKb of weak bases ⓘ |
| usedWith | molar conductivity measurements ⓘ |
| validWhen |
activity coefficients are approximately 1
ⓘ
α is small ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.