Cobalt (III) chloride forms several octahedral complexes with amonia. Which of the following will not give test for chloride ions with silver nitrate at `25^@C`?

Options

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

Answer

C

Explanation

As cobalt forms octahedral complexes for which coordination number = 6, the formulae of the given complexes will be
`[Co(NH_(3))_(5)Cl]Cl_(2), [Co(NH_(3))_(6)]Cl_(3)`,
`[Co(NH_(3))_(3)Cl_(2)]` and `[Co(NH_(3))_(4)Cl_(2)]Cl`
Thus, only (c) does not have any ionizable chloride ion.