Question

In [Cu(NH3)4]2+, the subscript 4 indicates which of the following?

A.
The oxidation number of Cu only
B.
The coordination number of Cu2+ only
C.
Both the oxidation number of Cu and the coordination number of Cu2+
D.
Neither the oxidation number of Cu nor the coordination number of Cu2+

Answer 1

The subscript 4 in [Cu(NH3)4]2+ indicates the B)coordination number of Cu2+.

Coordination number refers to the number of ligands attached to the central metal ion in a coordination complex. In the given complex, Cu2+ is the central metal ion and it is coordinated to four ammonia (NH3) ligands.

The subscript 4 in [Cu(NH3)4]2+ indicates the number of NH3 ligands attached to the Cu2+ ion, which is the coordination number of Cu2+. The oxidation number of Cu in this complex is +2, which is indicated by the Roman numeral II in the formula. Therefore, the correct answer is B.