Which of the following complexes will have the highest molar conductivity ?

Options

A. `CoCI_(3)` . `3NH_(3)`
B. `CoCI_(3)` . `4NH_(3)`
C. `CoCI_(3)` . `5NH_(3)`
D. `CoCI_(3)` . `6NH_(3)`

Answer

D

Explanation

The electrical conductivity of a solution of an ionic compound depends on:
(1) Concentration of solute
(2) Number of charges on the species which are formed on dissolution
Molar conductivity corresponds to a 1M solution and thus the concentration factor is removed. The total number of charges on the species formed when the complex dissolves in water can be deducted by complex dissolves in water can be deducted by comparison of its molar conductitity with that of known simple ionic materials.
`[Co(NH_(3))_(6)]C1_(3) rarr [Co(NH_(3))_(6)]^(3+) + 3C1^(-)`
`[Co(NH_(3))_(5)C1]C1_(2) rarr [Co(NH_(3))_(5)C1]^(2+) + 2C1^(-)`
`[Co(NH_(3))_(4)C1_(2)]C1 rarr [Co(NH_(3))_(4) C1_(2)]^(+) + C1^(-)`
`[Co(NH_(3))_(3)]C1_(3) rarr` No ionization
Total of 4 charges
`CaC1_(2) rarr Ca^(2+) + 2C1^(-)` `mo1^(-1) Scm^(-2)`
`260.8`
`CoC1_(3)` . `5NH_(3)` `261.3`
Total of 6 charges
`LaC1_(3) rarr La^(3+) + 3C1^(-)` `393.5`
`CoC1_(3)` . `6NH_(3)` `431.6`
These conductivities sugguest the same structures for the cobaltammoniachlorine as do the results for werner's AgC1 experiments complexes AgC1 experiments.