The reaction $\left[\mathrm{Co}(\mathrm{CN})_{5} \mathrm{H}_{2} \mathrm{O}\right]^{2-}+\mathrm{X}^{-} \rightarrow\left[\mathrm{Co}(\mathrm{CN})_{5} \mathrm{X}\right]^{2-}+\mathrm{H}_{2} \mathrm{O}$ follows a/an
(a)Interchange dissociative (Id) mechanism
(b)Dissociative (D) mechanism
(c)Associative (A) mechanism
(d)Interchange Associative (Ia) mechanism
Answer
Answer (as printed): A
Explanation
The reaction follows $\mathrm{S_N}$CB mechanism in which M-Y bond is fully broken before M-X bond begins to form. Thus, Id mechanism is the most evidential mechanism.