Question

The resistivity of a 0.2M solution of electrolyte is 5×10^-3 ohm cm.calculate it's molar conductivity.

Answer 1

Explanation:

1. 0.2M
2. resistivity 5×10^-3 ohm cm
3. calculate molar conductivity

Answer 2

Given,

Molarity of solution, M = 0.2 M

Resistivity, ρ = 5 × $10^{-3}$ Ω cm

To find,

The molar conductivity of the solution.

Solution,

In order to solve this problem correctly and easily, we can follow the given steps.

From what knowledge, we have of this chapter in  Chemistry we know that,

Κ = 1/ρ

Here,

K = Specific conductance of the solution which can be defined to be the amount of electricity the solution can conduct.

ρ = Resistivity

Thus,

K = $\frac{1}{(5)(10^{-3} )}$

K = 0.2 × $10^{3}$ $Scm^{-1}$

Thus, the specific conductance of the solution is calculated to be 0.2 × $10^{3}$ $Scm^{-1}$

We know that the formula for molar conductivity is

Λm = $\frac{(K)(1000)}{M}$

If we replace the values we will have,

Λm = $\frac{(K)(1000)}{M}$

= $\frac{(0.2)(10^{3} )(1000)}{0.2}$

= $10^{6}$ $Scm^{2}mol^{-1}$

Hence, the molar conductivity of the given solution was calculated to equal to $10^{6}$ $Scm^{2}mol^{-1}$.