coordination compounds

[sly moth]

not able to understand why (2) is answer and not (3). On calculating CFSE value, according to me, B>A. And H2O is also stronger ligand than F- then why oxidation number on Co is given more importance?

(JEE Main 26th Aug, 2021 PYQ)

[proper cape]

<@&1227988359910260737>

Note for OP

+solved @user1 @user2... to close the thread when your doubt is solved. Mention the users who helped you solve the doubt. This will be added to their stats.

[amber osprey]

Hey Adira, good spot.
Here is the stuff that matters for CFSE

1. 4d 5d element much more than 3d
2. Charge (3+ > 2+)
3. Ligand str

ligand str is the last thing in order of effects

[sly moth]

ohhhh

[sly moth]

demn

thankyou so much

[amber osprey]

We good, shall we close it out?

[sly moth]

yepp

+solved @amber osprey