C5

Question 1

MgCl2 electrical conductivity (2)

Answer 1

MgCl2 doesn’t conduct when solid because ions are fixed in lattice (1)
MgCl2 conducts when molten / aqueous because it has ‘mobile’ ions

Question 2

Describe and explain the electrical conductity of sodium oxide, Na2O and sodium in their solid and molten states (5)

Answer 2

M1: Sodium conducts in solid and molten states (1)
M2: Sodium has delocalised electrons (in both solid and liquid state
M3: Na2O conducts when molten and not when solid
M4: Molten Na2O has ‘ions’ which are mobile

M5: Solid Na2O has ‘ions’ which are fixed in position OR ‘ions’ are not mobile
AND
in an (ionic) lattice / structure