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
31–40 of 991
Question 31
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 32
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 33
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 34
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 35
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 36
2 marks · Hard
Answer and see the solution →A student explains that when a liquid is boiled, only the temperature of the liquid changes. Using particle theory, explain why this statement is incorrect.
Question 37
5 marks · Hard
Answer and see the solution →A sealed glass tube contains substance Y as a solid at −10 °C. The tube is slowly warmed to 90 °C. The melting point of Y is 12 °C and its boiling point is 80 °C.
(a)[1 mark]Name the state change that occurs when substance Y is heated from −10 °C to 20 °C.
(b)[1 mark]State the name of the process when Y changes from liquid at 75 °C to a gas at 85 °C.
(c)[1 mark]What is the name of the reverse process of the state change in part (b)?
(d)[2 marks]Explain, using particle theory, what happens to the arrangement and movement of the particles as Y changes from solid at −10 °C to liquid at 20 °C.
Question 38
2 marks · Hard
Answer and see the solution →Describe, using particle theory, what happens to the forces between particles and their movement when a gas is cooled to become a liquid.
Question 39
1 mark · Easy
Answer and see the solution →What is the name given to the process by which the particles of a liquid or gas spread out and mix without stirring?
Question 40
3 marks · Easy
Answer and see the solution →A student places a jar of coloured gas below a jar containing only air and quickly removes the lid between them.
(a)[1 mark]State what will eventually be seen in both jars.
(b)[2 marks]Explain why it takes some time for the colour to spread through both jars, using ideas about particles.