what does a dot mean in a chemical formula?

[yoyohomieg5432]

---

Members don't see this ad.

This is from AAMC test 8.. never seen that dot before

 

[AureatEagle]

This is from AAMC test 8.. never seen that dot before

The dot followed by water implies that the first molecule is hydrated. Every NiSO4 atom is being complexed by six water molecules in solution. Not a terribly important point to know.