Starter quiz
- Sort the states of matter and the temperatures at which changes of state occur into the correct order, starting with a substance in the solid state.
- 1⇔substance in the solid state
- 2⇔melting point
- 3⇔substance in the liquid state
- 4⇔boiling point
- 5⇔substance in the gas state
- Freezing and condensing are exothermic processes. Melting, evaporation and boiling are ______ processes.
- 'endothermic' ✓
- A block of pure ice is heated in a beaker until it has all melted. Which of the following statements are correct?
- All the ice will melt at the same time.
- The ice will melt gradually over time. ✓
- The particles in water are different to the particles in ice.
- The arrangement of the particles changes as the ice melts. ✓
- On average, the particles move faster as the temperature increases. ✓
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- Match the following keywords to their definition.
- melting⇔change from a solid state to a liquid state ✓
- boiling⇔change from a liquid state to a gas state ✓
- freezing⇔change from a liquid state to a solid state ✓
- condensing⇔change from a gas state to a liquid state ✓
- Which of the following statements describe what happens when a pure substance boils and changes from the liquid state to the gas state?
- the change of state can happen over a range of temperatures
- the change of state happens at an exact temperature ✓
- the temperature gradually decreases
- the temperature remains constant ✓
- the temperature gradually increases
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- Which of the following statements describes what happens when a pure substance freezes and changes from the liquid state to the solid state?
- the temperature gradually decreases
- the temperature remains constant ✓
- the temperature gradually increases
- the change of state happens at an exact temperature ✓
- the change of state can happen over a range of temperatures
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Exit quiz
Consider a heating curve (see image). The following statements are about some of the sections (e.g. ‘CD’ means the sloping part from C to D). Which of the statements are correct?- AB: temperature of pure solid substance increases as energy is transferred to it ✓
- AB: particles remain in fixed position but vibrations increase ✓
- BC: temperature does not change but particles start to move past each other ✓
- BC: temperature does not change but particles spread apart from each other
- DE: temperature does not change but particles spread apart from each other ✓
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The image shows three cooling curves. What do the ringed sections represent, in order from left to right?- condensing point; liquid state; freezing point
- condensing point; liquid state; solid state
- gas state; liquid state; freezing point ✓
- gas state; liquid state; solid state
- gas state; melting point; freezing point
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- Sort the following stages of a heating curve into the correct order, starting from a statement about the solid substance:
- 1⇔Temperature of the solid substance increases until it reaches its melting point.
- 2⇔Melting point: transferred energy is used to overcome forces of attraction.
- 3⇔At the melting point, the temperature stays the same.
- 4⇔Once all the substance is in the liquid state, the temperature rises again.
- 5⇔Boiling point: transferred energy is used to overcome forces of attraction.
- 6⇔At the boiling point, the temperature stays the same.
- 7⇔Once all the substance is in the gas state, the temperature rises again.
- In a heating curve experiment, the dependent variable is temperature, and the independent variable is ______.
- 'time' ✓
- Which of the following pieces of equipment would you use to measure the dependent variable in the heating curve experiment?
- beaker
- boiling tube
- Bunsen burner
- stopwatch
- thermometer ✓
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The image shows a curve for oxygen. This is a ______, although it starts at the melting point rather than with the substance in the solid state.- 'heating curve' ✓
Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- An experiment can be planned to measure the temperature change through continuous heating of a substance
- Energy is needed to overcome forces of attraction between particles so temperature does not change when changing state
- The change in state of pure substances can be seen on a heating/cooling curve as a horizontal line
- There is a change of energy, arrangement, and organisation of particles of a pure substance at each stage
Common misconception
Pupils struggle to understand what is taking place at the horizontal parts of the graph.
Be concise with your language and ask pupils to use the same language. 'have enough energy to overcome the forces of attraction between particles', 'to slide past each other', 'to move past each other'.
Keywords
Heating curve - shows temperature changes of a substance over time as it is heated.
Cooling curve - shows temperature changes of a substance over time as it is cooled.
Intermolecular forces - are forces between particles.
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