(i) What are the types of hybridisation of `NH_(4)^(+),CO_(3)^(2-),H_(2)S and SF_(6)`?
(ii) C-O bond is polar but `CO_(2)` does ot have a dipole moment. Why?

Explanation

(i) In `NH_(4)^(+) and H_(2)S` the central atom (N and S) undergoes `sp^(3)` hybridisation.
In `CO_(3)^(2-)` the central atom C is `sp^(2)` hybridised.
In `SF_(6)`, the central atom S undergoes `sp^(3)d^(2)` hybridisation.
(ii).