What is meant by water of crystallisation?
Answer and explanation
Correct answer: Fixed amount of water present in salt crystals
Water of crystallisation is the fixed number of water molecules chemically associated with the formula unit of certain crystalline salts. It is not merely moisture on the surface or any water used to dissolve a substance. For example, washing soda contains ten water molecules, Na₂CO₃·10H₂O, and blue copper sulphate contains five, CuSO₄·5H₂O. Therefore option A gives the correct definition; the other choices describe unrelated forms of water.
Frequently asked questions
What is the correct answer to this question?
Fixed amount of water present in salt crystals
Why is this the correct answer?
Water of crystallisation is the fixed number of water molecules chemically associated with the formula unit of certain crystalline salts. It is not merely moisture on the surface or any water used to dissolve a substance. For example, washing soda contains ten water molecules, Na₂CO₃·10H₂O, and blue copper sulphate contains five, CuSO₄·5H₂O. Therefore option A gives the correct definition; the other choices describe unrelated forms of water.
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.
