# Question #9ba12

$C u B {r}_{2} \left(s\right) + \text{excess } {H}_{2} O \left(l\right) \rightarrow C {u}^{2 +} \left(a q\right) + 2 B {r}^{-} \left(a q\right)$
$C {u}^{2 +} \left(a q\right)$ is a coordination complex, which we could reasonably represent at ${\left[C u {\left(O {H}_{2}\right)}_{6}\right]}^{2 +}$; its salts have a quite beautiful blue colour.