Question

The specific conductance of a 0.001 solution of KCl is 0.0014\[oh{m^{ - 1}}c{m^{ - 1}}\]. Find its equivalent conductance.

Answer 1

Hint: The reciprocal of the electrical resistance is called the conductance. The conductivity of a solution is defined as the conductance of a solution of 1 cm length and having 1 square cm as the area of cross-section. Alternatively, it may be defined as the “conductance of one-centimeter cube of the solution of the electrolyte”. The S.I unit of conductance is Siemens represented by the letter S.

Complete step by step solution:
In this question, the specific conductance is given and we have to calculate the equivalent conductance.
Given,
Specific conductance (k) of the KCl solution $ = 0.0014oh{m^{ - 1}}c{m^{ - 1}}$
Since it is a KCl solution so its valency is 1 due to which molarity is equal to its normality which is 0.001
We know that,
Equivalent conductance $ = \dfrac{{k \times 1000}}{{Normality}}$
$ = \dfrac{{0.0014 \times 1000}}{{0.01}}$ (since molarity is equal to normality so the normality will be 0.01)
$ = 140$ $S{m^2}e{q^{ - 1}}$

We have put the given values in the above formula to calculate the equivalent conductance and it is found to be 140 $S{m^2}e{q^{ - 1}}$.

Note: Note (in points)The conductance of an electrolyte depends upon the following factors.
Nature of the electrolyte: - The conductance of a solution depends upon the nature of the electrolyte, i.e. upon the number of ions present in the solution. The greater the number of ions, the greater will be the conductance of the solution. Strong electrolytes like HCl, NaCl, NaOH, etc. produce a large number of ions in the solution. The solution of strong electrolytes has high conductance. But weak electrolytes like $C{H_3}COOH$, $N{H_4}OH$, etc. produce fewer ions in solution and have less conductance.
The concentration of the solution: - The equivalent, as well as molar conductance of an electrolyte, also depends upon the concentration of its solution. Usually, the molar conductance increases by an increase in dilution (or decrease in concentration) of the solution. The reason is that on dilution, the dissociation of electrolytes goes on increasing.