What causes the blue colour of copper sulphate crystals?
Answer and explanation
Correct answer: Water of crystallisation
Hydrated copper sulphate crystals have the formula CuSO₄·5H₂O. The fixed water molecules incorporated into the crystal structure are called water of crystallisation and are associated with its characteristic blue appearance. Sodium ions, chlorine gas, and carbon dioxide are not responsible for this colour, so option A is correct.
Frequently asked questions
What is the correct answer to this question?
Water of crystallisation
Why is this the correct answer?
Hydrated copper sulphate crystals have the formula CuSO₄·5H₂O. The fixed water molecules incorporated into the crystal structure are called water of crystallisation and are associated with its characteristic blue appearance. Sodium ions, chlorine gas, and carbon dioxide are not responsible for this colour, so 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.
