Kohlrausch law of independent migration of ions
Weak electrolytes
Kohlrausch law of independent migration of ions
o
The Kohlrausch law of independent migration of ions states that limiting molar conductivity of an electrolyte can be represented as the sum of the individual contributions of the anion and cation of the electrolyte . o
Limiting equivalent molar conductivity of an electrolyte is the algebraic sum of limiting molar equivalent conductivities of its constituent ions .
o Mathematically ,
Where λo + = limiting equivalent conductivities of cation
λo - = limiting equivalent conductivities of anion .
Weak electrolytes
o
A substance which forms ions in an aqueous solution do not dissociate completely at moderate concentrations is known as weak electrolyte .
o For example , HC2H3O2 ( acetic acid ), H2CO3 ( carbonic acid ), etc . o The conductance of the solution increases with dilution of solution .