Why does the blue colour of copper sulphate disappear on heating?
Answer and explanation
Correct answer: Water of crystallisation is removed
Blue copper sulphate is hydrated CuSO₄·5H₂O. On heating, its water of crystallisation is driven off, producing anhydrous copper sulphate, which is white. The colour change is therefore due to loss of bound water, not addition of sodium or chlorine and not formation of carbon dioxide. Hence option A is correct.
Frequently asked questions
What is the correct answer to this question?
Water of crystallisation is removed
Why is this the correct answer?
Blue copper sulphate is hydrated CuSO₄·5H₂O. On heating, its water of crystallisation is driven off, producing anhydrous copper sulphate, which is white. The colour change is therefore due to loss of bound water, not addition of sodium or chlorine and not formation of carbon dioxide. Hence option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
