Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Principles of Chemistry
991 practice questions
Topics covered
- States of Matter102 practice questions
- Elements, Compounds and Mixtures69 practice questions
- Atomic Structure108 practice questions
- The Periodic Table103 practice questions
- Chemical Formulae, Equations and Calculations Part 119 practice questions
- Chemical Formulae, Equations and Calculations Part 2144 practice questions
- Ionic Bonding143 practice questions
- Covalent Bonding68 practice questions
- Metallic Bonding19 practice questions
- Electrolysis198 practice questions
Practice questions
11–20 of 423 · Normal
Question 11
3 marks · Normal
Answer and see the solution →Ammonium chloride can change directly from a solid to a gas when heated. Explain why the process observed is called sublimation, and describe what happens to the particles during this process.
Question 12
4 marks · Normal
Answer and see the solution →The table shows the melting and boiling points of three substances at standard pressure.
Melting and boiling points of substances Substance Melting point (°C) Boiling point (°C) A –15 58 B 112 212 C 75 –10 (a)[2 marks]At room temperature (20°C), name the physical state of each substance (A, B, and C).
(b)[2 marks]Explain why substance C cannot exist as a liquid at room temperature.
Question 13
1 mark · Normal
Answer and check →Which of the following processes describes a gas changing directly to a solid?
- A.Evaporation
- B.Condensation
- C.Deposition
- D.Melting
Question 14
2 marks · Normal
Answer and see the solution →Describe what happens to the forces between particles as a solid melts to form a liquid. Refer to particle theory in your answer.
Question 15
4 marks · Normal
Answer and see the solution →Complete the table below about the names of the processes for interconversion between all three states of matter.
(a)[2 marks]From state To state Process name Solid Liquid ? Liquid Gas ? Gas Liquid ? Gas Solid ? (b)[2 marks]Describe how the energy of the particles changes in the process from liquid to gas.
Question 16
3 marks · Normal
Answer and see the solution →A student heats 10 g of solid iodine in a sealed container. The iodine sublimes completely, forming a gas. The total mass of the container and its contents does not change during this process.
(a)[1 mark]State the process that occurs when solid iodine changes directly into a gas.
(b)[2 marks]Explain, using particle theory, why the mass of the container and its contents does not change when the solid turns into a gas. Include ideas about particles and their arrangement.
Question 17
2 marks · Normal
Answer and see the solution →Explain what is meant by diffusion in gases, using the idea of particles.
Question 18
4 marks · Normal
Answer and see the solution →(a)[1 mark]Figure 1 shows an apparatus used to investigate the diffusion of bromine gas.
Apparatus for diffusion of bromine gas State what you would observe if the lid between the two gas jars is removed.
(b)[2 marks]Explain why the observation described in (a) happens, using ideas about particles.
(c)[1 mark]Suggest why the bromine gas eventually spreads throughout both jars.
Question 19
3 marks · Normal
Answer and see the solution →Two cotton wool plugs, one soaked in concentrated ammonia solution and the other in concentrated hydrochloric acid, are placed at opposite ends of a long glass tube.
After some time, a white ring of ammonium chloride forms closer to the hydrochloric acid end.
Explain why the white ring forms closer to the hydrochloric acid end rather than in the middle. Use ideas about particles and diffusion.
Question 20
1 mark · Normal
Answer and check →Which statement best describes diffusion in gases?
- A.Particles move from a region of low concentration to high concentration.
- B.Particles remain completely still until energy is added.
- C.Particles move from a region of high concentration to low concentration.
- D.Particles only move if they are liquids.