Factors Affecting Conductivity (i) Nature of electrolyte The | JEE NEET MATERIALS

Factors Affecting Conductivity
(i) Nature of electrolyte The strong electrolytes like
KNO KCl 3
, , NaOH, etc. are completely ionised in aqueous
solution and have high values of conductivity (molar as well as
equivalent). The weak electrolytes are ionised to a lesser extent
in aqueous solution and have lower values of conductivity (molar
as well as equivalent).


(ii) Concentration of the solution The concentrated solutions
of strong electrolytes have significant interionic attractions,
which reduce the speed of ions and lower the value of Λ m and Λeq.
The dilution decreases such attractions and increases the value
of Λ m and Λeq. The limiting value, Λ Λ m m or 0 ∞
(the molar
conductivity at zero
concentration or at infinite
dilution) can be obtained by
extrapolating the graph.
In case of weak
electrolytes, the degree of
ionisation increases on
dilution which increases
the value of Λ m and Λeq. The limiting value Λ m
0
cannot be
obtained by extrapolating the graph. The limiting value, Λ m
0
,
for weak electrolytes is obtained by Kohlrausch law.


(iii) Temperature The increase of temperature decreases
inter-ionic attractions and increases kinetic energy of ions and
their speed. Thus, Λ m and Λeq increase with temperature.