What is the valency of copper?How to find the chemical formula of copper sulphate
Copper is a transition metal - it is not in any group. One of the properties of a transition metal is variable valency. This means that they can have different charges. So, for example, Iron Oxide can be FeO (where iron has a valency of two and therefore it is written Iron (II) Oxide) or Fe2O3 (where iron has a valency of three and therefore it is written Iron (III) Oxide).
Anyway, back to your question. In the case of copper sulphate, we find that it is always copper (II) sulphate, so that makes it CuSO4, where the Cu has a 2+ charge.
The reason for this is that of the two possible oxidation states, 1+ and 2+ (3+ and 4+ do occur but are very rare), 1+ is less stable and can only form compounds with the halides and oxygen. Most other common copper compounds are 2+.
CuSO4. Actually it is often hydrated, then it's CuSO4.5H2O.
Copper is a transition metal - it is not in any group. One of the properties of a transition metal is variable valency. This means that they can have different charges. So, for example, Iron Oxide can be FeO (where iron has a valency of two and therefore it is written Iron (II) Oxide) or Fe2O3 (where iron has a valency of three and therefore it is written Iron (III) Oxide).
Anyway, back to your question. In the case of copper sulphate, we find that it is always copper (II) sulphate, so that makes it CuSO4, where the Cu has a 2+ charge.
The reason for this is that of the two possible oxidation states, 1+ and 2+ (3+ and 4+ do occur but are very rare), 1+ is less stable and can only form compounds with the halides and oxygen. Most other common copper compounds are 2+.
CuSO4. Actually it is often hydrated, then it's CuSO4.5H2O.
