Question

Which of the following has least conductivity in aqueous solution? 

Options

• \[\ce{Co(NH3)4Cl3}\]

• \[\ce{Co(NH3)3Cl3}\]

• \[\ce{Co(NH3)5Cl3}\]

• \[\ce{Co(NH3)6Cl3}\]

Answer 1

\[\ce{Co(NH3)3Cl3}\]

Explanation:

The number of ions dissociated in a solution has a direct relationship with conductivity.

\[\ce{Co(NH3)4 Cl3 -> [Co\underset{2 ions}{(NH3)4} Cl2] + Cl-}\]

\[\ce{Co(NH3) Cl3 -> [Co\underset{1 ion}{(NH3)} (Cl3)]}\]

\[\ce{Co(NH3)5 Cl3 -> [Co\underset{3 ions}{(NH3)5} Cl]^{2+} + 2Cl-}\]

\[\ce{Co(NH3)6 Cl3 -> [Co\underset{4 ions}{(NH3)6}]^{3+} + 3Cl-}\]

∴ CO(NH₃)₆ Cl₃ will produce higher number of ions and has higher conductivity.