JEE Main 22 Jan 2025 Shift 2 Paper

Crystal field splitting energy (∆)∝ charge or oxidation state of central metal atom.
Crystal field splitting energy (∆)∝ Field strength of ligand (and chelation)
Crystal field stabilisation energy (CFSE) =[−0.4t2g. +0.6 eg] ∆∘ (for octahedral)

For,
‌[Co(en)3]3+:Co3+:t2g6eg0;CFSE=−2.4(∆0)1
‌[Co(NH3)6]3+:Co3+:t2g6eg0;CFSE=−2.4(∆0)2
‌[Co(NH3)6]2+:Co2+:t2g5eg2;CFSE=−0.8(∆0)3
‌[Co(NH3)4]2+:Co2+:e4t23;CFSE=−1.2∆t
‌(‌ as ‌:(∆t)=‌

4

9

(∆0)3)
‌∵‌‌∆t<(∆0)3<(∆0)2<(∆0)1