Copper, Extraction, Properties and Uses for SS 3

Class: SSS 3
Term: First Term
Week: 4
Age: 16 years
Duration: 45 minutes
Subject: Chemistry
Curriculum Theme: Metals and their Compounds
Previous Lesson: Tin and Transition Metals
Topic: METALS AND THEIR COMPOUNDS
Subject Matter: Copper: extraction of copper and uses of copper

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• Define copper as a metal.
• Describe the main steps involved in the extraction of copper from its ores.
• List at least five uses of copper.

Affective Domain

• Appreciate the economic importance of copper.
• Value the industrial processes involved in metal extraction.

Psychomotor Domain

• Draw a simple flow chart illustrating the extraction of copper.
• Identify samples of copper metal and its common ores.

Reference Materials

The following resources were used in planning this lesson:

• 2025 Revised 9 Years Basic Education Curriculum
• Relevant State Unified Scheme of Work
• Essential Chemistry for Senior Secondary Schools by O.D. Odunuga et al.
• The HeadTeacher Scheme of work

Instructional Materials

The teacher will teach this lesson with the aid of:

• Charts showing the extraction process of copper
• Samples of copper ore (e.g., chalcopyrite)
• Samples of refined copper metal
• Diagrams illustrating the Bessemer converter and electrolytic refining cell

Rationale for the Lesson

This lesson provides students with a foundational understanding of how an important metal like copper is obtained from its natural sources and its significance in various industries. It connects theoretical chemical knowledge to practical industrial applications, highlighting the relevance of chemistry in technology and everyday life.

Prerequisite/Previous Knowledge

Students should have a basic understanding of elements, metals, chemical reactions, and the concept of ores.

Lesson Content/Board Summary

Copper: Extraction and Uses

Extraction of Copper

Copper is primarily extracted from its sulphide ores, with chalcopyrite ((CuFeS_2)) being the most common. The extraction process involves several stages:

1. Concentration (Froth Flotation): The ore is crushed into a fine powder and mixed with water, oil, and a frothing agent. Air is blown through the mixture, creating froth that carries the lighter ore particles, separating them from heavier gangue (impurities).
2. Roasting: The concentrated ore is heated strongly in the presence of air. This converts iron sulphide to iron oxide and copper sulphide to copper(I) sulphide. Sulphur dioxide gas is produced.

   (2CuFeS_2(s) + 4O_2(g) rightarrow Cu_2S(s) + 2FeO(s) + 3SO_2(g))

3. Smelting: The roasted ore is mixed with silica ((SiO_2)) and heated in a reverberatory furnace. The iron oxide reacts with silica to form iron silicate slag ((FeSiO_3)), which is molten and floats on top of the heavier molten copper(I) sulphide (matte). The slag is removed.

   (FeO(s) + SiO_2(s) rightarrow FeSiO_3(l))

4. Bessemerisation: The molten matte ((Cu_2S)) is transferred to a Bessemer converter, and hot air is blown through it. Any remaining iron sulphide is oxidized to iron oxide and then forms slag with silica. Copper(I) sulphide is oxidized to copper(I) oxide, which then reacts with remaining copper(I) sulphide to produce molten copper, known as ‘blister copper’ due to the bubbles of (SO_2) escaping.

   (2Cu_2S(s) + 3O_2(g) rightarrow 2Cu_2O(s) + 2SO_2(g))

   (2Cu_2O(s) + Cu_2S(s) rightarrow 6Cu(s) + SO_2(g))

5. Refining (Electrolytic Refining): Blister copper is about 98% pure. For high purity (e.g., for electrical uses), it undergoes electrolytic refining.
   1. Impure copper acts as the anode (positive electrode).
   2. Thin sheets of pure copper act as the cathode (negative electrode).
   3. The electrolyte is an acidified solution of copper(II) sulphate.
   4. During electrolysis, copper from the impure anode dissolves into the electrolyte as (Cu^{2+}) ions, while pure copper deposits onto the cathode. More reactive metals from the anode dissolve and remain in the solution, while less reactive metals (e.g., silver, gold) fall to the bottom as anode sludge.

Uses of Copper

Copper is a versatile metal with numerous applications due to its excellent properties:

1. Electrical Wiring: It is an excellent conductor of electricity, making it ideal for electrical cables, wires, and components.
2. Plumbing and Roofing: Its corrosion resistance and malleability make it suitable for water pipes, roofing materials, and gutters.
3. Coinage: Copper and its alloys are used to make coins due to their durability and attractive appearance.
4. Alloys: Copper is alloyed with other metals to create materials with enhanced properties:
   1. Brass: An alloy of copper and zinc, used for musical instruments, decorative items, and fittings.
   2. Bronze: An alloy of copper and tin, used for sculptures, bells, and bearings.
   3. German Silver: An alloy of copper, zinc, and nickel, used for cutlery and decorative items.
5. Cookware: Its high thermal conductivity makes it suitable for pots, pans, and other cooking utensils.

Teaching Methods/Instructional Techniques

Discussion, Explanation, Question and Answer, Demonstration, Visual Aids

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Activating Prior Knowledge

Teacher’s Activity: The teacher greets the students and asks them to name some common metals and their uses, particularly asking about copper if they know any. The teacher then introduces copper as an important metal.

Pupils’ Activity: Students respond to the questions, sharing their knowledge of metals and their uses.

Learning Point: Common metals recall

Step 2: Introduction to Copper Extraction

Time: 8 minutes

Teaching Skill: Explanation/Visualisation

Teacher’s Activity: The teacher explains that copper is rarely found pure and is mostly extracted from its ores, showing samples of chalcopyrite. The teacher then introduces the first stages of extraction: concentration and roasting, explaining their purposes.

Pupils’ Activity: Students observe the ore samples and listen attentively to the explanation of the initial extraction steps.

Learning Point: Copper ore identification

Step 3: Smelting and Bessemerisation

Time: 8 minutes

Teaching Skill: Detailed Explanation

Teacher’s Activity: The teacher continues to explain the next stages of copper extraction: smelting and Bessemerisation. The teacher uses charts or diagrams to illustrate the processes and the chemical reactions involved, explaining the formation of slag and blister copper.

Pupils’ Activity: Students follow the explanation, ask questions for clarification, and observe the diagrams.

Learning Point: Smelting and Bessemerisation

Step 4: Electrolytic Refining

Time: 7 minutes

Teaching Skill: Demonstration/Explanation

Teacher’s Activity: The teacher explains the final stage of obtaining pure copper through electrolytic refining, detailing the roles of the anode, cathode, and electrolyte. A diagram of an electrolytic cell is used to illustrate the process.

Pupils’ Activity: Students pay attention to the explanation of electrolytic refining and observe the diagram.

Learning Point: Electrolytic refining process

Step 5: Uses of Copper

Time: 5 minutes

Teaching Skill: Listing/Discussion

Teacher’s Activity: The teacher discusses the various uses of copper, showing samples of copper wire or other copper items if available. The teacher relates the uses to copper’s properties (e.g., electrical conductivity for wiring).

Pupils’ Activity: Students contribute to the discussion, identify common uses of copper, and observe samples.

Learning Point: Diverse uses of copper

Step 6: Flow Chart of Extraction

Time: 3 minutes

Teaching Skill: Guided Drawing

Teacher’s Activity: The teacher guides students to create a simple flow chart summarizing the main steps of copper extraction on the board.

Pupils’ Activity: Students draw the flow chart in their notebooks, reinforcing the sequence of extraction steps.

Learning Point: Copper extraction flow chart

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is the most common ore of copper?
2. Briefly describe the roasting stage in copper extraction.
3. What is the purpose of electrolytic refining?
4. Mention three uses of copper.

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Copper extraction and uses recall

Step 8: Note-Taking

Time: 4 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on copper extraction and uses into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording lesson notes

Step 9: Conclusion

Time: 2 minutes

Teaching Skill: Consolidation

Teacher’s Activity: The teacher briefly summarizes the key points of copper extraction and its importance, encouraging students to appreciate the industrial applications of chemistry.

Pupils’ Activity: Students listen and ask any final questions.

Learning Point: Lesson summary reinforcement

Continuous Assessment/Further Study

Type: Homework

Instruction: Answer the following questions in your notebook:

1. Explain why copper is often electrolytically refined after initial extraction.
2. Research and write down two common alloys of copper, stating their compositions and one use for each.
3. Draw a well-labelled diagram of the electrolytic refining cell for copper.

Lesson Keywords

• Copper – A reddish-brown metallic element, highly conductive of heat and electricity.
• Chalcopyrite – The most common sulphide ore of copper ((CuFeS_2)).
• Froth Flotation – A method used to concentrate sulphide ores.
• Roasting – Heating an ore in air to convert sulphides to oxides or sulphides.
• Smelting – Heating an ore to extract the metal, often involving a flux to remove impurities as slag.
• Bessemerisation – A process used to convert molten matte into blister copper.
• Blister Copper – Impure copper obtained from Bessemerisation, containing trapped sulphur dioxide gas.
• Electrolytic Refining – A process using electrolysis to purify metals.

Differentiation

Support for weaker learners: Provide simplified diagrams and a step-by-step handout of the copper extraction process. Focus on identifying the main stages and a few key uses. Encourage peer tutoring.

Extension for faster learners: Challenge them to research the environmental impacts of copper extraction and the methods used to mitigate them, or to investigate other methods of copper extraction (e.g., hydrometallurgy).

Suggested Lesson Videos

For further understanding, students can search YouTube for:
extraction of copper chemistry SS3
uses of copper chemistry

Teacher Guide for Using This Lesson Plan

Before the lesson, ensure you have prepared visual aids such as charts of copper extraction and actual samples of copper ore and refined copper if possible. Begin by engaging students with their prior knowledge of metals. Systematically explain each stage of copper extraction, from concentration to electrolytic refining, using diagrams to clarify the processes and chemical equations. Emphasize the purpose of each step and the transformations occurring. Follow this by discussing the various practical uses of copper, linking them to its properties. Encourage students to ask questions throughout the lesson. Allow sufficient time for students to copy the Board Summary notes after the main teaching and evaluation. For weaker learners, provide simplified explanations and focus on the core concepts. For faster learners, encourage deeper research into related topics or environmental considerations. Always ensure a safe learning environment, especially when discussing industrial processes.