INTERMOLECULAR FORCES

Question 1

Why is ice less dense than water?

Answer 1

• H-O bonds in water are longer in water.

* Bonds are further apart in an open lattice.

Question 2

Why does water have a relatively high boiling point?

Answer 2

• Hydrogen bonds are the strongest intermolecular forces

* More energy needed to break the bonds

Question 3

Describe how Permanent Dipole-Dipole attractions arise.

Answer 3

• Polar/unsymmetrical molecules that have at least one permanent dipole.

Question 4

Describe how Van Der Waals’ forces arise.

Answer 4

• Non-polar/symmetrical molecules
• Temporary dipole forms in one molecule due to an uneven distribution of electrons
• Induces a dipole to be formed on a neighbouring molecule
• Van Der Waals’ forces arise between molecules