Which of the following has `ppi-dpi` bonding?

Options

A. `NO_3^-`
B. `SO_3^(2-)`
C. `BO_3^(3-)`
D. `CO_3^(2-)`

Answer

B

Explanation

In `SO_3^(2-)` , S is `sp^3` hybridised, so

`underset(("Sulphur atom in excited state"))(._16S=1s^2, 2s^2 2p^6),underset(sp^3 "hybridisation")ubrace(3s^2 3p_x^1 3p_y^1 3p_z^1)underset("Unhybridised")(3d_(xy)^1)`
In 'S' the three p-orbitals forms `sigma` bonds with three oxygen atoms and unhybridised d-orbital is involved in `pi`-bond formation
`O_8=1s^2 , 2s^2 2p_x^2 2p_y^1 2p_z^1`
In oxygen two unpaired p-orbitals are present , one is involved in `sigma` bond formation while other is used in `pi`-bond formation.
Thus, in `SO_3^(2-)` , p and d-orbitals are involved for `ppi-dpi` bonding.