Describe the process of crystallization of copper sulphate from its solution. Is this a physical or chemical change? Justify your answer.
Crystallization is a process used to obtain pure solid substances from their solutions in the form of crystals. To crystallize copper sulphate, one would typically heat a solution of copper sulphate and then allow it to cool slowly. As the solution cools, pure copper sulphate starts separating out as crystals. This is a physical change. It is considered a physical change because no new chemical substance is formed; only the physical state of copper sulphate changes from being dissolved in water to forming solid crystals. The chemical composition of copper sulphate () remains unchanged throughout the process.
Explanation
Key points for grading:
- Brief description of the crystallization process (e.g., heating solution, slow cooling).
- Correctly identifies it as a physical change.
- Justification: no new substance is formed, only change in state/form.
- Chemical composition remains the same ().