Question

Write the general electronic configuration of 3d series. Draw the structures of sulphuric acid and thiosulphuric acid.

Hint:

To draw structures of oxoacids, first determine the central atom (usually the least electronegative). Then, attach the required number of -OH groups corresponding to the number of acidic protons, and finally, satisfy the octet of the central atom using double bonds with the remaining oxygen atoms.

Answer 1

Part 1: General Electronic Configuration of 3d Series
The 3d series consists of elements from Scandium (Sc, Z=21) to Zinc (Zn, Z=30). The differentiating electron enters the 3d orbital. The general electronic configuration for the elements of the 3d series is:
\[ [\text{Ar}] \, 3d^{1-10} \, 4s^{1-2} \] where [Ar] represents the core configuration of Argon.

Part 2: Structures of Sulphuric Acid and Thiosulphuric Acid

Sulphuric Acid (H\(_2\)SO\(_4\)): Sulphur is the central atom, bonded to two hydroxyl (-OH) groups and two oxygen atoms via double bonds. It has a tetrahedral geometry around the sulphur atom.
Thiosulphuric Acid (H\(_2\)S\(_2\)O\(_3\)): The structure is similar to sulphuric acid, but one of the doubly-bonded oxygen atoms is replaced by a sulphur atom.