Question

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

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

Answer 1

The correct option is C 4.008 %

$Degreeofdissociation\left(\alpha \right)=\frac{molarconductivityatconc.c\left({\wedge }_m^c\right)}{molarconductivityatinfinitedilution\left({\wedge }_m^{\infty }\right)}$

$\left(\alpha \right)=\frac{9.54{\Omega }^{-1}c{m}^{2}mo{l}^{-1}}{238{\Omega }^{-1}c{m}^{2}mo{l}^{-1}}$

$=0.04008$

$=4.008$%