Chemistry - Electrochemistry Question with Solution | TestHub

Molar conductivity at infinite dilution for ${\text{CH}}_3\text{COOH}$ is given by Kohlrausch's law:

${\Lambda }_m^{\infty }={\lambda }^{\infty }({\text{CH}}_3{\text{COO}}^{-})+{\lambda }^{\infty }({\text{H}}^{+})$

${\Lambda }_m^{\infty }=50+350=400{\text{S cm}}^2{\text{mol}}^{-1}$

Degree of dissociation $\alpha$ is:

$\alpha =\frac{{\Lambda }_m}{{\Lambda }_m^{\infty }}=\frac{20}{400}=0.05$

Hydrogen ion concentration is:

$[{\text{H}}^{+}]=C\alpha =(5\times 10^{-2})\times 0.05=2.5\times 10^{-3}{\text{mol/dm}}^3$

Answer: $2.5\times 10^{-3}$