Question

The equivalent conductivity of a solution containing 2.54g of $CuS{O}_4$ per litre is 91.0 W^-1 cm² eq^-1. Its conductivity would be

• A. 1.45 x 10^-3W^-1cm^-1
• B. 2.17 x 10^-3W^-1cm^-1
• C. 2.90 x 10^-3W^-1cm^-1
• D. 2.9 x 10^-3W^-1cm^-1

Answer 1

Answer: (D)

The explanation for the correct option:

Option(D) 2.9 x 10^-3W^-1cm^-1

• ​The normality of Copper sulfate is calculated as:

  $Normality=\frac{Givenmass}{equivalentweight}\times \frac{1000}{volume}whereequivalentweight=\frac{molecularweight}{valency}$

  $=\frac{2.54}{\frac{159.5}{2}}\times \frac{1000}{1000}=0.032N$

• Hence, the conductivity can be calculated from the equivalent conductivity from the equation:

  ${\text{∧}}_{eq}=\frac{\text{κtimes1000}}{N}=91$

  $\therefore \text{κ}=\frac{N\times {\text{∧}}_{eq}}{1000}$

  $=\frac{91\times 0.032}{1000}$

  $=2.9\times {10}^{-3}{\text{Ω}}^{-1}c{m}^{-1}$

  Hence, option(D) $2.9\times {10}^{-3}{\text{Ω}}^{-1}c{m}^{-1}$ is the conductivity of copper sulfate.