Question

H₂ plusand H₂ minus have same bond order but H₂ plus ion is more stable. WHY?

Answer 1

Molecular configuration of H₂⁺ and H₂^- ions is:
${H_2}^{+}=\sigma 1s^1$
${H_2}^{-}=\sigma 1s^2\sigma *1s^1$
Bond order = $\frac{1}{2}\left[N_b-N_a\right]$

Bond order of H₂⁺ and H₂^- = $\frac{1}{2}$

Since, there is an electron in anti bonding orbital of H₂^- ion, therefore it has higher energy than H₂⁺ ion and hence H₂⁺ ion is more stable.