Question

Why we put brackets in some chemical formulas​

Answer 1

Answer:

Brackets help in two ways. They can 1) reduce the amount of work, and 2) remove ambiguity from a structure.

Explanation:

The reason is that you need to put a bracket around the complex ion to show how many of those whole complex ions there are in the compound.

Answer 2

Explanation:

If there's more than one complex ion in the compound, then brackets are needed. The reason is that you need to put a bracket around the complex ion to show how many of those whole complex ions there are in the compound.