The rate of the substitution reaction of $\left[\mathrm{Co}(\mathrm{CN})_{5} \mathrm{Cl}\right]^{3-}$ with $\mathrm{OH}^{-}$to give $\left[\mathrm{Co}(\mathrm{CN})_{5}(\mathrm{OH})\right]^{3-}$
(a)is inversely proportional to the concentration of $\mathrm{OH}^{-}$
(b)depends on the concentrations of both $\left[\mathrm{Co}(\mathrm{CN})_{5} \mathrm{Cl}\right]^{3-}$ and $\mathrm{OH}^{-}$
(c)depends on the concentration of $\left[\mathrm{Co}(\mathrm{CN})_{5} \mathrm{Cl}\right]^{3-}$ only
(d)is directly proportional to the concentration of $\mathrm{OH}^{-}$ only
Answer
Answer: C ✓ checked by 4AB · confidence high
Explanation
[Co(CN)₅Cl]³⁻ has no N–H, so no conjugate-base path: the dissociative substitution rate depends only on the complex (c).