Magnetic moment, ionic conductance and colligative properties are useful in deciding structure/constitution of a given unknown complex compound. If molar conductivity of complex is almost equal to that of NaCl and it does not exhibits stereoisomerism then the complex will be :
(1) [Co(CO_3)(en)_2]Br
(2) [Co(CO_3)(H_2O)_2(NH_3)_2]Br
(3) [Co(CN)(NH_3)_5]Br_2
(4) [Co(CO_3)(NH_3)_4]Br