Edexcel IGCSE Chemistry 1.42 Giant ionic lattices

Practise explaining high melting points by linking giant ionic lattices, oppositely charged ions and the energy needed to overcome attractions.

Exam points

explain high melting points using giant ionic lattices and strong electrostatic attractions
compare melting points from tables by contrasting ionic lattices with molecular or metallic structures

[Maximum number: 3]

This is a question about metals and their compounds.

In the absence of air, magnesium reacts with sulfur to form the ionic compound magnesium sulfide, MgS

Explain why magnesium sulfide has a very high melting point.

M1 strong (electrostatic) force of attraction

M2 between magnesium ions $/ \mathrm{Mg}^{2+}$ and sulfide ions $/ \mathrm{S}^{2-}$ ions

M3 large amount/lot of (heat/thermal) energy needed to overcome forces/attraction

ALLOW strong ionic bonds but No M1 or M2 if between atoms/molecules or any reference to intermolecular forces / covalent bonds

ACCEPT between oppositely charged ions

ACCEPT between positive and negative ions

ACCEPT large amount/lot of (heat/thermal) energy needed to break the bonds

IGNORE more energy

No M3 if reference to overcoming / breaking intermolecular forces / covalent bonds

All question bank results loaded

1.42 Giant ionic lattices question 1