Question

The conductivity of a weak mono-basic acid in 0.2 N solution at ${20}^{o}C$ is $0.0023Sc{m}^{-1}$ and the equivalent conductivity at infinite dilution is $160.2Sc{m}^{2}e{q}^{-1}$. The degree of dissociation (in %) of weak acid is:

Answer 1

$\Lambda =\frac{1000\kappa }{C}=\frac{1000\times 0.0023Sc{m}^{-1}}{0.2N}=11.5Sc{m}^{2}e{q}^{-1}$.
The degree of dissociation $\alpha =\frac{\Lambda }{{\Lambda }_{\infty }}=\frac{11.5Sc{m}^{2}e{q}^{-1}}{160.2Sc{m}^{2}e{q}^{-1}}=0.07$
This corresponds to 7%.