• question_answer Which method can be used to distinguish $[Co{{(N{{H}_{3}})}_{6}}][Cr{{(N{{O}_{2}})}_{6}}]$ and $[Cr{{(N{{H}_{3}})}_{6}}][Co{{(N{{O}_{2}})}_{6}}]$ A) By measurement of their conductivity B) By titration method C) By precipitation method with $AgN{{O}_{3}}$ D) By electrolysis of their aqueous solutions

 The given compounds are isomeric. They can be distinguished by electrolysis of their aqueous solution. On electrolysis of its aqueous solution the complex ions of cobalt i.e.${{\left[ Co{{(N{{H}_{3}})}_{6}} \right]}^{3+}}$ of the complex $[Co{{(N{{H}_{3}})}_{6}}][Cr{{(N{{O}_{2}})}_{6}}]$ moves towards cathode (i.e., negative electrode) and on this electrode finally cobalt would be deposited. On electrolysis of aqueous solution of the complex ion of chromium ${{[i.e.,Cr{{(N{{H}_{3}})}_{6}}\}}^{3+}}]$ of the complex $[Cr{{(N{{H}_{3}})}_{6}}][Co{{(N{{O}_{2}})}_{6}}]$ moves towards cathode (i.e., negative electrode) and on this electrode chromium would finally be deposited.