Regrettably, there is no chemical compound with the formula BrF9. Currently, a bromine (Br) atom is only capable of combining with a maximum of 7 fluorine (F) atoms, forming a very strong and reactive compound, Bromine heptafluoride (BrF7). This substance is often used in strong oxidizing reactions.
Regarding BrF7, this pale yellow liquid has an unpleasant smell that is quite characteristic of halogen compounds. It can react with water to produce HF, a toxic and severely corrosive substance. BrF7 can also react with flammable metals and non-metals.
In the lab, BrF7 can be synthesized from BrF3 and O2 under specific temperature and pressure conditions. However, due to its dangerous nature and difficulty to control, the synthesis of BrF7 is not usually carried out in school laboratories.
In reality, there is no chemical compound with the formula BrF9. This is primarily due to the limitations in the number of bonds that a bromine atom can form. Therefore, BrF9 does not exist in chemistry.