Question

The homonuclear complex in the following is:

• A. \([\text{Co}(\text{NH}_3)_4\text{Br}_2]^+\)
• B. \([\text{Co}(\text{C}_2\text{O}_4)(\text{NH}_3)_4]^+\)
• C. \([\text{Co}(\text{NH}_3)_6]^{3+}\)
• D. \([\text{Co}(\text{CN})_4\text{Cl}_2]^0\)

Hint:

In a homonuclear complex, all atoms directly bonded to the central metal must be of the same element, like all nitrogen in \([\text{Co}(\text{NH}_3)_6]^{3+}\).

Answer 1

The Correct Option is C

A homonuclear complex has all coordinating atoms of the same element. Let's check: - (1) \([\text{Co}(\text{NH}_3)_4\text{Br}_2]^+\): Coordinating atoms are N (from \(\text{NH}_3\)) and Br. Not homonuclear.
- (2) \([\text{Co}(\text{C}_2\text{O}_4)(\text{NH}_3)_4]^+\): Coordinating atoms are O (from oxalate) and N. Not homonuclear.
- (3) \([\text{Co}(\text{NH}_3)_6]^{3+}\): All coordinating atoms are N (from \(\text{NH}_3\)). Homonuclear.
- (4) \([\text{Co}(\text{CN})_4\text{Cl}_2]^0\): Coordinating atoms are C (from \(\text{CN}^-\)) and Cl. Not homonuclear.
Thus, the homonuclear complex is \([\text{Co}(\text{NH}_3)_6]^{3+}\).
Thus, the correct answer is option 3.