A sample of Substance Z can exist as a solid, liquid, or gas depending on the temperature and pressure.
Under a pressure of 1.5 atm1.5\text{ atm}1.5 atm, gaseous Substance Z transitions directly into a solid at −80 ∘C-80\,^\circ\text{C}−80∘C without condensing into a liquid first. This process is known as deposition. Describe what happens to the movement and arrangement of the particles of Substance Z when it undergoes deposition. Use the particle model in your answer.
The table below shows the melting point, boiling point, and sublimation/deposition point of Substance Z at two different pressures:
| Pressure (atm) | Melting point ( ∘C\,^\circ\text{C}∘C) | Boiling point ( ∘C\,^\circ\text{C}∘C) | Sublimation/Deposition point ( ∘C\,^\circ\text{C}∘C) |
|---|---|---|---|
| 1.51.51.5 | — | — | −80-80−80 |
| 8.08.08.0 | −45-45−45 | 151515 | — |
State a temperature and a pressure at which Substance Z is a liquid. Explain your answer by referring to the data in the table.
27 exam-style questions on OCR GCSE Chemistry The particle model. Each one has a worked solution and a mark scheme showing where the marks go.