Which of the following cannot be used as a standard solution for the determination of the cell constant of a conductivity cell?

$\wedge_{AgCl}^{\infty}$ can be obtained by:

The limiting molar conductivities of the given electrolytes at $298 \ K$ follow the order: $\lambda^{\circ}_{(K^{+})} = 73.5, \lambda^{\circ}_{(Cl^{-})} = 76.3, \lambda^{\circ}_{(Ca^{2+})} = 119.0, \lambda^{\circ}_{(SO_{4}^{2-})} = 160.0 \ S \ cm^{2} \ mol^{-1}$.

The specific conductivity of $N/10$ $KCl$ solution at $20\,^oC$ is $0.0212\,ohm^{-1}\,cm^{-1}$ and the resistance of the cell containing this solution at $20\,^oC$ is $55\,ohm$. The cell constant is ............. $cm^{-1}$.

What happens when the solution of an electrolyte is diluted?

An electrolyte of a polymer-salt complex of poly(ethylene oxide)-LiCF$_{3}$SO$_{3}$ is shaped into a free standing circular film of $20 \ mm$ diameter and a thickness of $20 \ \mu m$. When it is sandwiched between $2$ stainless steel circular electrodes of the same diameter, this cell exhibits a conductance of $\frac{314}{5} \ S$. What is the specific conductivity of the electrolyte?