A student analyses a solution of an unknown transition metal salt.
The experimental observations are recorded in the table below:
| Test | Observation |
|---|---|
| Reaction with aqueous sodium hydroxide, NaOH(aq)\text{NaOH(aq)}NaOH(aq) | Blue precipitate |
| Reaction with acidified aqueous silver nitrate, AgNO3(aq)\text{AgNO}_3\text{(aq)}AgNO3(aq) | Cream precipitate |
What is the formula of the salt?
CuBr2\text{CuBr}_2CuBr2
CuBr\text{CuBr}CuBr
FeBr2\text{FeBr}_2FeBr2
CuCl2\text{CuCl}_2CuCl2
