What causes the blue colour of copper sulphate crystals?
Answer and explanation
Correct answer: Water of crystallisation
Blue copper sulphate crystals are hydrated copper sulphate, CuSO₄·5H₂O. The definite water molecules held within the crystal lattice are called water of crystallisation, and their presence gives the crystals their characteristic blue appearance. Sodium ions, chlorine gas, and hydrogen gas are not constituents responsible for this colour. Hence, option A is the best answer.
Frequently asked questions
What is the correct answer to this question?
Water of crystallisation
Why is this the correct answer?
Blue copper sulphate crystals are hydrated copper sulphate, CuSO₄·5H₂O. The definite water molecules held within the crystal lattice are called water of crystallisation, and their presence gives the crystals their characteristic blue appearance. Sodium ions, chlorine gas, and hydrogen gas are not constituents responsible for this colour. Hence, option A is the best answer.
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.
