Question

How do you balance `B_2Br_6 + HNO_3 -> B(NO_3)_3 + HBr`?

Answer 1

For a start, your starting material is `BBr_3`.........

Explanation:

And another thing, while `""^(-)B(NO_3)_4` is known, I am pretty sure that `B(NO_3)_3` is UNKNOWN. There was something about its synthesis in the old Russian literature, but given the source, its existence would be fairly suspect........

As an hypothetical reaction, we could write........

`BBr_3+ 3HNO_3 +3NEt_3rarrB(NO_3)_3 + 3Et_3N*HBr`

Note that `BBr_3` reacts very violently with water, and its aqueous chemistry is unknown.