The $\mathrm{Cl}-\mathrm{Co}-\mathrm{Cl}$ bond angle values in a fac- $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{3} \mathrm{Cl}_{3}\right]$ complex is/are :

Decreasing order towards SN 1 reaction for the following compounds is:

$\mathrm{KMnO}_4$ oxidises $\mathrm{I}^{-}$ in acidic and neutral/faintly alkaline solutions, respectively, to :

In the above conversion of compound $(\mathrm{X})$ to product $(\mathrm{Y})$, the sequence of reagents to be used will be: