Physical and chemical changes

Physical and Chemical Changes
Topic 6. Chemical Energetics 
26 February 2024
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ChemistrySecondary EducationAge 12,13

This lesson contains 21 slides, with text slides.

Items in this lesson

Physical and Chemical Changes
Topic 6. Chemical Energetics 
26 February 2024

Slide 1 - Slide

Our Learning Map

Slide 2 - Slide

Our Learning Map
exercise mentally by completing classwork 6 to describe the extraction of iron in the blast furnace
- State the symbol equations for the extraction of iron from hematite
(a) C + O2 → CO2
(b) C + CO2 → 2CO
(c) Fe2O3 + 3CO → 2Fe + 3CO2
(d) CaCO3 → CaO + CO2 
(e) CaO + SiO2 → CaSiO3

Slide 3 - Slide

Recall
  • (a) What are the three raw materials added to the top of the blast furnace?
  • (b) What chemical reactions are involved in iron extraction from hematite?

Slide 4 - Slide

Extraction of iron from hematite
  • Coke burns in the hot air, forming carbon dioxide. The reaction is exothermic, giving off heat and heating the furnace.
  •  At the high temperatures in the furnace, more coke reacts with carbon dioxide, forming carbon monoxide. Carbon dioxide has been reduced to carbon monoxide.
  •  Carbon monoxide reduces the iron(III) oxide in the iron ore to form iron. This will melt and collect at the bottom of the furnace, where it is tapped off.  
  • Limestone (calcium carbonate) is added to the furnace to remove impurities in the ore. The calcium carbonate in the limestone thermally decomposes to form calcium oxide. 
  • The calcium oxide formed reacts with the silicon dioxide, an impurity in the iron ore, to form calcium silicate. This melts and collects as a molten slag floating on the molten iron tapped off separately. 

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Classwork 6 - Extraction of iron
  • Goal - Write the three raw materials added to the top of the blast furnace. Sequence (arrange) the steps in extracting iron from hematite by numbering them correctly. Write the word/symbol equations for the reactions in the arranged steps.
  • Product/Output - Completed worksheet
  • Standards - Correct responses.
timer
20:00

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Plenary Discussion

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Physical and Chemical Changes
Topic 6. Chemical Energetics 
26 February 2024

Slide 8 - Slide

Our Learning Map

Slide 9 - Slide

Our Learning Map
exercise mentally by completing classwork 6 to describe the extraction of iron in the blast furnace
create a poster to show examples of physical and chemical changes and provide an explanation for your choice

Slide 10 - Slide

Our Learning Map
analyse a video about the complete extraction process of iron from hematite in the blast furnace
discuss further the differences between physical and chemical changes during the hinge-point discussion
create a poster to show examples of physical and chemical changes and provide an explanation for your choice

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Physical and Chemical Changes
Topic 6. Chemical Energetics 
26 February 2024

Slide 12 - Slide

Chemical or Physical Change?

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Correcting Misconception
All changes involving substances are chemical changes.

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Correcting Misconception
All changes involving substances are chemical changes.

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Physical and Chemical Changes
Topic 6. Chemical Energetics 
26 February 2024

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Collaborative work - Physical and Chemical Changes Poster
  • Goal and output - Create a poster (using colouring and art materials) to show examples of physical and chemical changes; include at least 2 reasons why your examples show physical and chemical changes
  • Standards - examples of changes, artistic expression, reasons provided, neatness and presentation
timer
20:00

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Hinge-point discussion
  • What have you learned from the activity?

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Physical and Chemical Changes
Topic 6. Chemical Energetics 
26 February 2024

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Closing: Lesson Key Points

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Demo: Physical vs Chemical Change
  • Observe.
  • Write your observations.
  • Share.

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