Question

The shape of sulphate ion is:
A. Hexagonal
B. Square planar
C. Trigonal bipyramidal
D. Tetrahedral

Answer 1

Hint: The sulphate ion is the anion with negative charge. The empirical formula of sulphate ion is $SO_4^{2 - }$ where the central atom is sulphur and it is bonded to two oxygen atoms with double bonds and two oxygen atoms with single bonds. The oxidation state of sulphate ion is -2.

Complete step by step answer:
The sulphate or the sulphate ion is a polyatomic anion which contains different atoms in the anion. The anions are the negatively charged species formed by the loss of electrons. The sulphate ion contains one sulphur atom and four oxygen atoms with -2 oxidation state. The empirical formula of the sulphate ion is $SO_4^{2 - }$. The sulphates are referred to as the salts of sulphuric acid and are prepared from sulphuric acid.
The shape of sulphate ion is shown below.

In this structure, the sulphur atom is bonded with two oxygen atoms with double bond and with two oxygen with single bond with -2 oxidation state.
The shape of the sulphate anion is tetrahedral as four bonds are present around the central atom and no lone pair is present on the central atom. The bond angle between the atoms bonded to the central atom is the 109.5 degree.
Thus, the shape of sulphate ions is tetrahedral.
Therefore, the correct option is C.

Note:
The VSEPR theory is applied to find out the geometry and the shape of the molecule depending on the bond pairs and lone pairs present in the structure. The shape of the chemical compound is also based on the hybrid orbital. The molecule or ion with tetrahedral shape has $s{p^3}$ hybridization at the central atom.