Question

At ${25}^{\circ }C$ molar conductance of $0.1$ molar aqueous solution of ammonium hydroxide is $9.54oh{m}^{-1}c{m}^{2}mo{l}^{-1}$ and at infinite dilution its molar conductance is $238oh{m}^{-1}c{m}^{2}mo{l}^{-1}.$ The degree of ionization of ammonium hydroxide at the same concentration and temperature is : -

• A. $4.008\%$
• B. $40.800\%$
• C. $20.800\%$
• D. $2.080\%$

Answer 1

The correct option is A $4.008\%$

Molar conductance at $0.1M$ concentration, ${\lambda }_c=9.54{\Omega }^{-1}c{m}^{2}mo{l}^{-1}$
Molar conductance at infinite dilution, ${\lambda }_{\infty }=9.54{\Omega }^{-1}c{m}^{2}mo{l}^{-1}$

$\%\alpha =\frac{{\lambda }_c}{{\lambda }_{\infty }}\times 100=\frac{9.54}{238}\times 100=4.008\%$