Physical Changes:
* Color Change: Anhydrous copper sulfate (CuSO₄) is white, but when heated, it absorbs water from the air and turns blue. This is a reversible change, meaning it can be reversed by adding water.
* Dehydration: Heating copper sulfate pentahydrate (CuSO₄·5H₂O) drives off the water molecules, resulting in anhydrous copper sulfate. This change is also reversible by adding water.
Chemical Changes:
* Decomposition: When heated to higher temperatures (above 650°C), copper sulfate undergoes decomposition. This involves the breakdown of the compound into simpler substances:
* Copper sulfate decomposes into copper oxide (CuO) and sulfur trioxide (SO₃).
* The sulfur trioxide further decomposes into sulfur dioxide (SO₂) and oxygen (O₂).
* The overall reaction can be represented as:
* CuSO₄ → CuO + SO₃
* SO₃ → SO₂ + ½ O₂
These chemical changes are irreversible, meaning they cannot be reversed by simply adding water.
Summary:
Heating copper sulfate causes both physical changes (color change and dehydration) and chemical changes (decomposition). The specific changes depend on the temperature and duration of heating.
