The statement that is not correct is: "molecules of ice, water and water vapour have equal intermolecular distances."
Explanation:
- Ice, water, and water vapour are different states of water. They have different intermolecular distances because the intermolecular forces between their molecules are different.
- In ice, the intermolecular forces are the strongest due to hydrogen bonding, which results in a rigid and orderly arrangement of water molecules with a fixed intermolecular distance.
- In liquid water, the intermolecular forces are weaker than in ice, and the intermolecular distance is more variable.
- In water vapour, the intermolecular forces are weakest among the three, and the intermolecular distance is the largest.
Therefore, the statement that molecules of ice, water and water vapour have equal intermolecular distances is not correct.