Chapter 15

The resistance of a \(0.02 \mathrm{~N}\) solution of an electrolyte \(\mathrm{MgCl}_{2}\) was found to be 210 ohm at \(298 \mathrm{~K}\) using a conductivity cell with a cell constant of \(0.88 \mathrm{~cm}^{-1} .\) Calculate conductivity and equivalent conductivity and molccular conductivity of solution.

Calculate equivalent and molar conductivities at infinite dilute for \(\mathrm{CaCl}_{2}\) using the data given below : \(\Lambda^{0}\) for \(\mathrm{Ca}^{2+}=119.0 \mathrm{~S} \mathrm{~cm}^{2} \mathrm{~mol}^{-1}\) and \(\Lambda^{0}\) for \(\mathrm{Cl}^{-}=76.3 \mathrm{~S} \mathrm{~cm}^{2} \mathrm{~mol}^{-1}\)

The conductivity of \(0.001028 \mathrm{M}\) acetic acid is \(4.95 \times 10^{-5} \mathrm{~S} \mathrm{~cm}^{-1}\). Calculate its dissociation constant if \(\Lambda^{0}\) for acetic acid is \(390.5 \mathrm{~S} \mathrm{~cm}^{2} \mathrm{~mol}^{-1}\)

How much charge is required for the reduction of (a) 1 mole of \(\mathrm{Al}^{3+}\) to \(\mathrm{Al}\) (b) 1 mole of \(\mathrm{Cu}^{2+}\) to \(\mathrm{Cu}\) (c) 1 mole of \(\mathrm{MnO}_{4}^{4-}\) to \(\mathrm{Mn}^{2+}\) (d) 1 mole of \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}\) to \(\mathrm{Cr}^{3+}\)