The molar conductivity of acetic acid at infinite dilution is $390.7 Sc{m}^2 mo{l}^{-1}$ and for 0.01 M acetic acid is
$3.907 Sc{m}^2 mo{l}^{-1}$. The degree of dissociation and pH of the solution is ?

	$\left(\alpha \right)$	pH
1	0.1	3
2	0.02	4
3	0.001	5
4	0.01	4

Degree of dissociation

$\left(\alpha \right)=\frac{{\wedge }_m}{{\wedge }_m^0}=\frac{3.907}{390.7}=0.01$

${\mathrm{CH}}_3\mathrm{COOH} \rightleftharpoons {\mathrm{CH}}_3{\mathrm{COO}}^{-}+{\mathrm{H}}^{+}$

$\text{Initial conc.}$   C              0                  0

Final conc.  $C(1-\alpha )$   C$\alpha$              C$\alpha$

So,  $\left[H^{+}\right]=C\alpha =0.01\times 0.01={10}^{-4}\mathrm{M}$

$pH=-\log \left[H^{+}\right]=-\log {10}^{-4}$

$\mathrm{pH}=4$