Question

The central atom/ions in coordination compounds are referred to as:

• A. Lewis base
• B. Lewis acid
• C. Bronsted acid
• D. Bronsted base

Answer 1

The Correct Option is B

The central atom or ion in coordination complexes is identified as a Lewis acid.

This designation stems from specific chemical principles:

1. Lewis Acid Defined: A Lewis acid is a chemical entity capable of accepting an electron pair. Within coordination chemistry, the central atom/ion functions as a Lewis acid by accepting electron pairs from ligands. Ligands, in turn, operate as Lewis bases, donating these electron pairs.
2. Nature of Coordination Compounds: These compounds feature a central atom/ion bonded to surrounding molecules or ions, known as ligands. The central metal ion's electron-pair accepting capacity draws ligands, forming a stable structural arrangement.
3. Illustrative Case: In the coordination compound [Cu(NH₃)₄]²⁺, copper (Cu) serves as the central ion. It functions as a Lewis acid by accepting electron pairs from the ammonia (NH₃) molecules.

Consequently, the central atom/ion in coordination compounds is accurately classified as a Lewis acid.