Arrange the following in the increasing order order of their bond order : `O_(2), O_(2)^(+), O_(2)^(-)` and `O_(2)^(2-)` :

Options

A. `O_(2)^(- -) , O_(2)^(-),O_(2)^(+),O_(2)`
B. `O_(2)^(+),O_(2),O_(2),^(-),O_(2)^(- -)`
C. `O_(2),O_(2)^(+),O_(2)^(-),O_(2)^(- -)`
D. `O_(2)^(- -),O_(2)^(-),O_(2),O_(2)^(+)`

Answer

D

Explanation

Molecular orbital electronic configuration of `O_(2)` is
`(sigma 1 s)^(2)(sigma ^(**)1s)^(2)(sigma 2 s)^(2)(sigma^(**)2s)^(2)(sigma 2p_(2))^(2)(pi2p_(x))^(2)(pi2p_(y))^(2)(pi^(**)2p_(x))^(1)(pi^(**)2p_(x))^(1)(pi^(**)2p_(y))^(1)`
`:.` B.O. of `O_(2)=1/2(10-6)=2`
Molecular orbital electronic configuration fo `O_(2)^(+)` is
`(sigma 1s)^(2)(sigma^(**)1s)^(2)(sigma 2s)^(2)(sigma^(**)2s)^(2)(sigma2p_(z))^(2)(pi2p_(x))^(2)(pi2p_(y))^(2)(pi^(**)2p_(x))^(2)(pi^(**)2p_(y))^(1)`
`:.` B.O. of `O_(2)^(-)=1/2(10-7)=1.5`
Molecular orbital electronic configuration of `O_(2)^(2-)` is
`(sigma 1s)^(2)(sigma^(**)1s)^(2)(sigma2s)^(2)(sigma^(**)2s)^(2)(sigma2p_(z))^(2)`
`(pi2p_(x))^(2)(pi2p_(y))^(2)(pi^(**)2p_(7))^(2)`
`:.` B.O. of `O_(2)^(2-)=1/2(10-8)=1.0`
`:.` Increasing of B.O.is
`O_(2)^(2-)ltO_(2)^(-)ltO_(2)ltO_(2)^(+)`