![Second-order rate constant for the reaction between [Co(NH3)5X]n+ (n = 3 for X = NH3 and H2O](https://www.gkseries.com/blog/wp-content/uploads/2023/09/Second-order-rate-constant-for-the-reaction-between-CoNH35Xn-n-3-for-X-NH3-and-H2O.jpg)
Q. Second-order rate constant for the reaction between [Co(NH3)5X]n+ (n = 3 for X = NH3 and H2O; n = 2 for X = Cl–) and [Cr(H2O)6]2+ at room temperature varies with the X as
(A) NH3 > H2O > Cl– (B) Cl– > H2O > NH3
(C) NH3 > Cl– > H2O (D) H2O > NH3 > Cl–
Ans: Cl- > H2O > NH3
![Second-order rate constant for the reaction between [Co(NH3)5X]n+ (n = 3 for X = NH3 and H2O](https://www.gkseries.com/blog/wp-content/uploads/thumbs_dir/Generally-the-coordination-number-and-the-nature-of-the-electronic-absorption-band-f-→-f-transition--qd0p49gjr3ug7e7k9fbgjti9ra2s9nzy9o6y2lfgvw.jpg)
![Second-order rate constant for the reaction between [Co(NH3)5X]n+ (n = 3 for X = NH3 and H2O](https://www.gkseries.com/blog/wp-content/uploads/thumbs_dir/For-an-inverse-spinel-AB2O4-the-A-and-B-respectively-can-be-qd0pnqo5diicshx0iuf57wk4wq2lrvbpm2v630jry4.jpg)
![Determine the correctness (or otherwise) of the following Assertion [A] and the Reason [R]](https://www.gkseries.com/blog/wp-content/uploads/2023/10/Determine-the-correctness-or-otherwise-of-the-following-Assertion-A-and-the-Reason-R.jpg)
