Which among the following aqueous salt solutions is used in a conductivity cell to determine the cell constant?

The specific conductivity of a $0.01 \ M$ salt solution is $1.061 \times 10^{-4} \ S \ cm^{-1}$. The molar conductivity of this solution is:

Conductivity of a conductor is

The metal which is the best conductor of electricity is

Write a note on specific conductivity $(k)$.

Resistance of a conductivity cell at $298 \ K$ for $0.0100 \ M \ KCl$ is $161.8 \ \Omega$. Resistance becomes $190 \ \Omega$ when $0.005 \ M \ NaOH$ solution is filled in this cell. Calculate: $(i)$ cell constant,$(ii)$ specific conductivity for $NaOH$ solution,and $(iii)$ molar conductivity.