Kohlrausch law

Kohlrausch law

source : AskIITians

Kohlrausch law-

According to this law,

” At infinite dilution , when ionisation is complete, each ion makes its contribution towards equivalent conductance ( or molar conductance) of the electrolyte and at infinite dilution equivalent or molar conductance is given by the sum of the equivalent  conductances of two ions (cations and anions).

Λ⁺_m =  Λ⁰₊    +    Λ⁰_–

Λ⁰₊ = equivalent or molar conductance of cation at infinite dilution

Λ⁰_– = equivalent or molar conductance of  anion at infinite dilution

Another form of  law,

Λ⁺_m =  Λ⁰_{+ +}   +    Λ⁰_{– –}

_{+ and –  are number of cations and anions}

Another form of Kohlrausch law,

Λ_m = Λ⁰_m – K√ C

Λ_m = molar conductance

Λ⁰_m = molar conductance at infinite dilution

K = Kohlrausch constt.

C = concentration

or

Λ_eq = Λ⁰_eq – K√ C

Λ_eq  =  equivalent  conductance

Λ⁰_eq  = equivalent  conductance at infinite dilution

” At low concentration for strong electrolyte , molar or equivalent conductance both vary linearly with square root of conductance”