A chemical storage unit may reach any temperature from −40 ∘C-40\,^\circ\mathrm{C}−40∘C to 20 ∘C20\,^\circ\mathrm{C}20∘C.
| Substance | Melting point (∘C^\circ\mathrm{C}∘C) | Boiling point (∘C^\circ\mathrm{C}∘C) |
|---|---|---|
| K | −18 | 68 |
| L | −75 | −48 |
| M | −52 | 34 |
| N | −61 | 8 |
A substance is required to remain liquid throughout storage. Which substance meets this requirement?
M
N
L
K
122 exam-style questions on OCR GCSE Chemistry 2.3 Properties of materials, covering 2.3.1 Carbon bonding and the variety of organic compounds, 2.3.2 Diamond, graphite, fullerenes and graphene, 2.3.3 Bond strength, changes of state and predicting states, 2.3.4 Bulk properties and types of bonding, and 2.3.5 Nanoparticles: scale, surface area, uses and risks. Each one has a worked solution and a mark scheme showing where the marks go.