Which of the following ions has tetrahedral geometry and `sp^3` - hybridisation for its central atom ?

Options

A. `BH_4 ^-`
B. `NH_2 ^-`
C. `CO_3 ^(2-)`
D. `H_3 O^+`

Answer

A

Explanation

(a) Boron-htydride ion`(BH_4^(-)` has `sp^3`-hybridisation. Therefore, it is tetrahedral geometry.

(b) In `NH_2^(-)` molecule, the number of sigma bond is 2 and the number of lone pairs is 2, i.e. `sp^3`-hybridisation. Due to presence of 2 lone pairs, `NH_2^(-)` molecule will be bent shape similar to water.

(c) The carbonate ion, `CO_3^(2-)` has a trigonal planar geometry, i.e. carbon is `sp^2`-hybridised.

(d) In `H_3O^+`, hybridisation of oxygen is `sp^3` and structure of `H_3O^+` ion will be pyramidal.