Question

When $O_2$ changes to $O_2^{-}$ the O - O bond distance increases and bond order decreases.
If true enter 1, else enter 0.

• A. 1

Answer 1

The correct option is A 1
$O_2$has 16 electrons
$(\sigma 1s{)}^2,({\sigma }^{\ast }1s{)}^2,(\sigma 2s{)}^2,({\sigma }^{\ast }2s{)}^2,(2p_z{)}^2,(\pi {)}^4,({\pi }^{\ast }{)}^2$
a is the number of electrons in bonding molecular orbitals and
b is the number of electrons in antibondng molecular orbitals.
Bond Order$=\frac{1}{2}(10-6)$
$=2$
$O_2^{-}$has 17 electrons
$(\sigma 1s{)}^2,({\sigma }^{\ast }1s{)}^2,(\sigma 2s{)}^2,({\sigma }^{\ast }2s{)}^2,(2p_z{)}^2,(\pi {)}^4,({\pi }^{\ast }{)}^3$
Bond Order$=\frac{1}{2}(10-7)$
$=1.5$
hence bond order decreases and bond distance increases as bond distance is inversely proportional bond order.