Complete Question:
Suppose a cobalt atom in the +3 oxidation state formed a complex with two bromide (Br-) anions and four ammonia (NH3) molecules. write the chemical formula of this complex.
Answer:
[Co(NH₃)₄]⁺Br₂
Explanation:
The cobalt atom with +3 oxidation is represented as Co⁺³, and if it's bonded to two bromide ions, and four ammonia molecules. The molecules that are bonded to the metal atom (Co) are called complexing agents.
In the representation, we first put the molecules that surround the metal atom, forming an anion with the oxidation of the metal:
[Co(NH₃)₄]⁺³
Then, the ions are put in the formula. Because there are two bromides ion, each one with 1 minus charge, only 2 plus charged will be neutralized, and the complex will be:
[Co(NH₃)₄]⁺Br₂
