Limiting molar conductivity of NH₄OH (i.e., ${\mathrm{\Lambda }}_{\mathrm{m}\left({\mathrm{NH}}_4\mathrm{OH}\right)}^0$ is equal to -

1. ${\mathrm{\Lambda }}_{\mathrm{m}\left(\mathrm{NaOH}\right)}^0+{\mathrm{\Lambda }}_{\mathrm{m}\left(\mathrm{NaCl}\right)}^0-{\mathrm{\Lambda }}_{\mathrm{m}\left(\mathrm{NaOH}\right)}^0$

2. ${\mathrm{\Lambda }}_{\mathrm{m}\left(\mathrm{NaOH}\right)}^0+{\mathrm{\Lambda }}_{\mathrm{m}\left(\mathrm{NaCl}\right)}^0-{\mathrm{\Lambda }}_{\mathrm{m}\left({\mathrm{NH}}_4\mathrm{Cl}\right)}^0$

3. ${\mathrm{\Lambda }}_{\mathrm{m}\left({\mathrm{NH}}_4\mathrm{OH}\right)}^0+{\mathrm{\Lambda }}_{\mathrm{m}\left({\mathrm{NH}}_4\mathrm{Cl}\right)}^0-{\mathrm{\Lambda }}_{\mathrm{m}\left(HCl\right)}^0$

4. ${\mathrm{\Lambda }}_{\mathrm{m}\left({\mathrm{NH}}_4\mathrm{Cl}\right)}^0+{\mathrm{\Lambda }}_{\mathrm{m}\left(\mathrm{NaOH}\right)}^0-{\mathrm{\Lambda }}_{\mathrm{m}\left(\mathrm{NaCl}\right)}^0$

Molar conductivities $(\wedge {°}_m)$ at infinite dilution of NaCl, HCl and $C{H}_{3}COONa$ are 126.4, 425.9 and 91.0 S cm² mol^-1 respectively. $(\wedge {°}_m)$  for $C{H}_{3}COOH$  will be:

1.  $180.5$ $S$ $c{m}^{\mathrm{2 }}mo{l}^{-1}$

2.  $290.8$ $S$ $c{m}^{\mathrm{2 }}mo{l}^{-1}$

3.  $390.5$ $S$ $c{m}^{\mathrm{2 }}mo{l}^{-1}$

4.  $425.5$ $$ $S$ $c{m}^{\mathrm{2 }}mo{l}^{-1}$

The molar conductance of $\frac{\mathrm{M}}{32}$ solution of a weak monobasic acid is 8.0 ohm^-1 cm² and at infinite dilution is 400 ohm^-1 cm². The dissociation constant of this acid is: 

1. $1.25\times {10}^{-5}$

2. $1.25\times {10}^{-6}$

3. $6.25\times {10}^{-4}$

4. $1.25\times {10}^{-4}$

Kohlrausch's law states that at: