Cobalt (III) chloride forms several octahedral complexes with ammonia. Which of the following will not give test for chloride ions…

Cobalt (III) chloride forms several octahedral complexes with ammonia. Which of the following will not give test for chloride ions with silver nitrate at $25^\circ C$?
A $CoCl_3\cdot 3NH_3$
B $CoCl_3\cdot 4NH_3$
C $CoCl_3\cdot 5NH_3$
D $CoCl_3\cdot 6NH_3$

Detailed Solution

$CoCl_3\cdot 3NH_3$ is $[Co(NH_3)_3Cl_3]$: all three chlorides are coordinated inside the sphere.
No chloride ion is ionisable, so $[Co(NH_3)_3Cl_3] \xrightarrow{AgNO_3}$ no precipitate.

Werner's theory in past papers

2 questions from this chapter have appeared across 2 exam years.

Keep going

Practise Werner's theory All 2 questions This chapter in 2015 AIPMT-I