Which of the following pair of complexes are isomeric with each other but their aqueous solutions exhibit different molar conductivities.explain
(a) [PtCl2(NH3 )4]Br2 and [PtBr2(NH3)4]Cl2 (b) [CoCl2(NH3)4]NO2 and [CoCl(NO2)(NH3)4]Cl (c) [Co(NO2)(NH3 )5]Cl2 and [Co(ONO)(NH3)5]Cl2
(d) [CoBr(NH3)5]SO4 and [Co(SO4)(NH3)5]Br
Ans: (d)
Molar conductivity depends upon:
(i) the charge on cation and anion
(ii) number of ions in solution
(iii) size of ions
In aqueous solutions, the coordination compounds are split into their coordination sphere and counter ions.
(a) [PtCl2(NH3)4]Br2(aq) [PtCl2(NH3)4]2+ + 2Br-
and [PtBr2(NH3)4]Cl2(aq) [PtBr2(NH3)4]2+ + 2Cl-
Both are isomeric. Both have total 3 ions in solution. Also the size of Br- and Cl- is similar. So there will negligible difference in their molar conductivities.
(b) [CoCl2(NH3)4]NO2(aq) [CoCl2(NH3)4]+ + NO2-
and [CoCl(NO2)(NH3)4]Cl(aq) [CoCl(NO2)(NH3)4]+ + Cl-
Both are isomeric. Both have total 2 ions in solution. The charges in both cases are also same. But there is slight size difference between NO2- and Cl-. So there would be slight difference in their molar conductivities.
(c) [Co(ONO)(NH3)5]Cl2(aq) [Co(ONO)(NH3)5]2+ + 2Cl-
and [Co(NO2)(NH3)5]Cl2(aq) [Co(NO2)(NH3)5]2+ + 2Cl-
Both are isomeric. There is no difference in number, charge and size of ions in both the cases. Thus, there will be no difference in their molar conductivities.
(d) [CoBr(NH3)5]SO4 [CoBr(NH3)5]2+ + SO42-
and [Co(SO4)(NH3)5]Br [Co(SO4)(NH3)5]+ + Br-
Both are isomeric. In first isomer, there are total two ions produced with 2 unit charges on each ions, while in second isomer, there are also two ions but with 1 unit charge on each ion. Also, there is large difference in the sizes of SO42- and Br-. Thus, these isomers will exhibit large difference in their molar conductivities.
Molar conductivity depends upon:
(i) the charge on cation and anion
(ii) number of ions in solution
(iii) size of ions
In aqueous solutions, the coordination compounds are split into their coordination sphere and counter ions.
(a) [PtCl2(NH3)4]Br2(aq) [PtCl2(NH3)4]2+ + 2Br-
and [PtBr2(NH3)4]Cl2(aq) [PtBr2(NH3)4]2+ + 2Cl-
Both are isomeric. Both have total 3 ions in solution. Also the size of Br- and Cl- is similar. So there will negligible difference in their molar conductivities.
(b) [CoCl2(NH3)4]NO2(aq) [CoCl2(NH3)4]+ + NO2-
and [CoCl(NO2)(NH3)4]Cl(aq) [CoCl(NO2)(NH3)4]+ + Cl-
Both are isomeric. Both have total 2 ions in solution. The charges in both cases are also same. But there is slight size difference between NO2- and Cl-. So there would be slight difference in their molar conductivities.
(c) [Co(ONO)(NH3)5]Cl2(aq) [Co(ONO)(NH3)5]2+ + 2Cl-
and [Co(NO2)(NH3)5]Cl2(aq) [Co(NO2)(NH3)5]2+ + 2Cl-
Both are isomeric. There is no difference in number, charge and size of ions in both the cases. Thus, there will be no difference in their molar conductivities.
(d) [CoBr(NH3)5]SO4 [CoBr(NH3)5]2+ + SO42-
and [Co(SO4)(NH3)5]Br [Co(SO4)(NH3)5]+ + Br-
Both are isomeric. In first isomer, there are total two ions produced with 2 unit charges on each ions, while in second isomer, there are also two ions but with 1 unit charge on each ion. Also, there is large difference in the sizes of SO42- and Br-. Thus, these isomers will exhibit large difference in their molar conductivities.