What causes the blue colour of copper sulphate crystals?
Answer and explanation
Correct answer: Water of crystallisation
The governing concept is water of crystallisation in hydrated salts. Blue copper sulphate crystals are CuSO4·5H2O, so each formula unit contains a fixed number of water molecules within the crystal structure. This hydrated form has the characteristic blue appearance. Sodium ions, chlorine gas and carbon dioxide are not responsible for the colour of copper sulphate crystals.
Frequently asked questions
What is the correct answer to this question?
Water of crystallisation
Why is this the correct answer?
The governing concept is water of crystallisation in hydrated salts. Blue copper sulphate crystals are CuSO4·5H2O, so each formula unit contains a fixed number of water molecules within the crystal structure. This hydrated form has the characteristic blue appearance. Sodium ions, chlorine gas and carbon dioxide are not responsible for the colour of copper sulphate crystals.
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.
