Question

The shape of ${H_2}S{O_4}$ is :
A. tetrahedral
B. pyramidal
C. planar
D. t-shaped

Answer 1

Hint: We know that, The Hybridization is that the concept in which atomic orbitals combine to make a new hybridized orbital which successively, influences molecular geometry and bonding properties.
We know that the electrons which are present at the outermost shell of an atom are called valence electrons and the valency of an electron is that the number of electrons through which atom accepts or donate to make a bond.

Complete step by step answer:
To be able to predict the shape of molecules, it is important to learn about the Valence Shell Electron Pair Repulsion Theory, also known as the VSEPR Theory.
This theory provides a simple procedure to predict the shape of molecules. The main postulates of VSEPR theory are as follows:
(i) The shape of a molecule depends upon the number of valence shell electron pairs (bonded or non-bonded) around the central atom.
(ii) Pairs of electrons in the valence shell repel one another since their electron clouds are negatively charged.
(iii) These pair of electrons tend to occupy such positions that minimize repulsion and thus maximize distance between them.
(iv)The valence shell is taken as a sphere with the electron pairs localizing on the spherical surface at maximum distance from one another.
(v) A multiple bond is treated as if it is a single electron pair and the two or three electron pairs of a multiple bond are treated as a single super pair.
(vi)Where two or more resonance structures can represent a molecule, the VSEPR model is applicable to any such structure.
The repulsive interactions of electron pairs decrease in the order: Lone pair-Lone pair>Lone pair-Bond pair>Bond pair-Bond pair.
For the prediction of geometrical shapes of molecules with the help of VSEPR theory, it is convenient to divide molecules into two categories as: (i) Molecules in which the central atom has no lone pair and (ii) molecules in which the central atom has one or more lone pair.
In the molecule, ${H_2}S{O_4}$,there is a sulphite ion which has a lone pair of electrons( due to two hydrogens) and three bond pairs attached to the three oxygen atoms. Hence according to the VSEPR theory, the arrangement of atoms is in a tetrahedral manner and therefore the shape is predicted to be trigonal pyramidal.
We can draw the structure of sulfurous acid as,

So, the correct answer is Option B.

Note: The key aspects of the VSEPR theory is important to predict the geometry of a large number of molecules, especially the compounds of p-block elements accurately. It must also be noted that the lone pair electrons occupy more space as compared to the bonding pairs of electrons. Calculating the number of lone pairs and bond pairs and using the tables above is sufficient to predict the shape of a large number of molecules.