4. (a) Force 1: Van der Waals’ (1)

4. (a) Force 1: Van der Waals’ (1)

Force 2: dipole - dipole (1)

Force 3: hydrogen bonding (1)

OR London, Dispersion, temporary dipole

(b) (i) covalent between atoms (1)

OR within molecule

Van der Waals’ between molecules (1)

(ii) molecular. (1)

(iii) Bonds (or forces) between molecules must be broken or loosened (1)

OR VdW forces

OR intermolecular forces

Mention of ions CE=0

(dipole-) dipole in HCl (1)

OR V. dW

H-bonding is stronger than dipole-dipole or V. dW. (1)

OR H-bonding is a strongest intermolecular force for 3rd mark

(ii) HI bigger molecule than HCl (1)

OR Heavier, more e’s, more electron shells, bigger Mr, more polarisable

Therefore the forces between HI molecules are stronger (1)

QL mark (Look for unambiguous statements using correct terminology)

(d) (i) ionic (1)

Strong forces between ions (1)

OR lots of energy required to break bonds

(ii) All bonds must be broken(1)

mention of molecules etc CE=0

(e) macromolecular (1)

OR giant molecule / lattice or correct diagram

Strong covalent bonds (1)

OR lots of energy required to break bonds

[17]

5. (a) carbon (1) 1

(b) covalent (1) 1

(d) vibrate (1)
about a fixed position (1) 2

(e) bonds break (or loosen) (1)
atoms (or molecules) free to move (1) 2

(f) electrons not free in silicon dioxide (1)
delocalised electrons in graphite (1) 2

[9]