JEE Main20199 Jan 2019Morning ShiftChemistryChemical Bonding and Molecular StructureActual
According to molecular orbital theory, which of the following is true with respect to Li 2 + and Li 2 - ?
Options
- AL i 2 + is stable and L i 2 - is unstable
- BBoth are unstable
- CBoth are stable
- DL i 2 + is unstable and L i 2 - is stable
Correct answer
C. Both are stable
Step-by-step solution
According to molecular orbital theory L i 2 + has 5 electrons - σ 1 s 2 σ * 1 s 2 σ 2 s 1 L i 2 - has 7 electrons - σ 1 s 2 σ * 1 s 2 σ 2 s 2 σ * 2 s 1 b o n d o r d e r = e l e c t r o n i n b o n d i n g m o l e c u l a r o r b i t a l - E l e c t r o n i n A n t i b o n d i n g m o l e c u l a r o r b i t a l 2 Bond order of L i 2 + = 3 - 2 2 = 1 2 Bond order of L i 2 - = 4 - 3 2 = 1 2 As both have similar bond order, both L i 2 + and L i 2 - will be stable. Note: L i 2 - will be relatively unstable to L i 2 + a