Cobalt(II) bromide hexahydrate.
<h3>Explanation</h3>
Name of the hydrate of an ionic compound:
Name of the ionic compound + Number of water molecules + "hydrate".
What's the name of the ionic compound CoBr₂ without all the H₂O?
There are two ions in this compound:
As a transition metal, cobalt Co can form ions of more than one possible charges. Hence, it's necessary to indicate the oxidation state of cobalt in the name. The oxidation state of Co in Co²⁺ is +2. The Co²⁺ ion will be called cobalt(II).
Bromine Br is a nonmetal. The Br⁻ ion is named as bromide.
Thus the name of the salt without H₂O: CoBr₂ Cobalt(II) bromide.
There are six water molecules for every one formula unit of the salt. Hence the prefix hexa-.
Name of the hydrate:
Cobalt(II) bromide hexahydrate.
