Question

What is the relation between specific and equivalent conductance?

Answer 1

There is a subtle difference between specific conductance and equivalent conductance.

As you might have heard before, for specific conductance is actually conductivity of a solution(for cases of electrochemistry), meaning it is the conductance of a given solution for a very special case.

Specific Conductance or conductivity is the conductance of a given solution enclosed in a cell having two electrodes of unit area and are separated by 1cm.

We know that Conductance(C)= Conductivity(K)*A/l

Thus, Conductivity or Specific Conductance(K)=Conductance*l/A

While Equivalent Conductance is also a specific case but a little different than that of the previous one.

Equivalent Conductance is the conductance of all the ions produced by one gram equivalent of an electrolyte in a given solution.

Let Vcm^3 of solution is considered.

We can say that the equivalent conductance is directly proportional to the volume of solution considered, as more the ions, more the conductance.

Thus, Equivalent Conductance(Λ )= Equivalent Conductivity(k)*V(in cm^3)…….(1)

So, here, Equivalent Conductance is the conductance of ions present in Vcm^3 of solution containing 1gm equivalent of the electrolyte, while Equivalent Conductivity is the specific case for unit volume.

Now, to relate this equation with gm equivalent(as defined for gm equivalent), we know that Normality= No. of gm equivalents/Volume(in lit). As we have considered a solution containing 1 gm-equivalent.

Thus, Equivalent Conductance(Λ)= Equivalent Conductivity(k)*1000/Normality.

1000 is multiplied as Equivalent Conductance is defined for volume in cm^3 while Normality is defined for volume in litres.

Now, this was all about Specific Conductance and Equivalent Conductance, now coming to your question for relation between them.

With reference to used symbols for various quantities.

K=C*l/A

Multiplying with A in numerator and denominator in RHS.

K=C*V/(A^2)

If we consider the solution for unit volume.

K=C*V

Now, you can see that this equation is very similar to equation(1).

So, now you should understand that specific conductance is just a concept to quantify and express conductivity of a solution, while Equivalent Conductivity is a special case of it, while considering gm-equivalents, similarly we may also have molar conductivity which is considered for moles in a solution.

So, you can directly, say that Equivalent Conductance = Specific Conductance(when considered for gm-equivalents)* Volume.

Answer 2

Answer:

the relationship between equivalent and specific conduction is