Which octahedral coordination compound will show maximum conductivity in aqueous solution if all $N{H}_3$ act as ligands?

The correct option is A $CoC{l}_3.6N{H}_3$

The octahedral coordination compound $CoC{l}_3.6N{H}_3$ will show maximum conductivity in aqueous solution if all $N{H}_3$ act as ligands.

$CoC{l}_3.6N{H}_3$ can be represented as $\left[Co\right(N{H}_3{)}_6]C{l}_3$. It ionises in aqueous solution and gives maximum number of ions.

$\left[Co\right(N{H}_3{)}_6]C{l}_3\to [Co(N{H}_3{)}_6{]}^{3+}+3C{l}^{-}$

Note:

$CoC{l}_3.5N{H}_3$ can be represented as $\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2$. It ionises in aqueous solution to give lesser number of ions.

$\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2\to [Co(N{H}_3{)}_{5}Cl{]}^{2+}+2C{l}^{-}$

$CoC{l}_3.4N{H}_3$ can be represented as $\left[Co\right(N{H}_3{)}_{4}C{l}_2]Cl$. It ionises in aqueous solution to give lesser number of ions.

$\left[Co\right(N{H}_3{)}_{4}C{l}_2]Cl\to [Co(N{H}_3{)}_{4}C{l}_2{]}^{+}+C{l}^{-}$