Which statements are correct for the peroxide ion ?
(1) It has five completely filled anti - bonding molecular orbitals
(2) It is diamagnetic
(3) It has bond order one
(4) It is isoelectronic with neon

Options

A. (iii) and (iv)
B. (i) , (ii) and (v)
C. (ii) and (iii)
D. (i) and (v)

Answer

C

Explanation

Peroxide ion is `O_(2)^(2-)`
E.C. `sigma_(1s)^(2) sigma_(1s)^(**2)sigma_(2s)^(2)sigma_(2s)^(**2)sigma_(2p_(z))^(2)pi_(2p_(x))^(2)pi_(2p_(y))^(2)pi_(2p_(x))^(**2)pi_(2p_(y))^(**2)`
It tha four completely filled antibonding molecular
obitals . It is diamgnetic .
Bond order `= (1)/(2) (10 - 8) = 1`
Total electrons present = 18
Thus , it is not isoelectronic with neon `._ ""(10)Ne`
Hence , only option (ii) and (iii) are correct