MYP 6: Scheme of work
6. Laboratory techniques
3. Materials and mixtures
3.1 Materials around us - Science world 1, p50
6. Laboratory techniques
Objective: To introduce the students to a new and potentially hazardous environment and explain safe practice.
Discuss the need for specialised apparatus for the handling of chemicals and materials.
Potential Chemical Hazards:
Demonstrate some examples from the chemical store:
Symbols used to convey information about chemicals:
Emphasise that the scientist's job is to be able to handle these materials safely and link this with the laboratory rules:
" Always use the correct apparatus
Draw hazard symbols in exercise books and explain what each one means.
Objective: To introduce and familiarise the students with the apparatus and equipment used in the study of chemical science and its correct use
The students should classify each piece as apparatus for measuring, containing, supporting, delivering liquid, heating, testing etc. This may be done as a class discussion.
Tabulate the information by drawing each piece of apparatus in the exercise book in 2 dimensions (ruler and pencil) with labels and its purpose.
The lesson may be completed by selection of apparatus from a choice and explaining its purpose. The students may be instructed for example to collect 50cm3 of water in a 250cm3 conical flask.
Objective: To introduce the concept of testing as applied to chemical substances and materials
The concept of a test should be introduced as a means of obtaining information about the nature of a material.
Materials tests to involve three stages (before - during - after):
Students to have explained the procedure of recording the test.
What is done
1. Add 1 spatula of copper carbonate to 25cm3 of sulphuric acid in a small beaker with stirring.
Before: Sulphuric acid clear - colourless liquid
During: Effervescence (bubbling)
After: Blue clear solution
Write-up: Criterion B- communication
Five major classes of materials, each one chosen for its properties. Discuss properties and reasons for using materials.
Activity 29 pp 112-3:
Classification of materials - Science World 1, p50
Questions page 51.
Activity 30 pp114-5:
Comparing synthetic and natural fibres.
Introduction - discussion
What were the original resource materials for all tools and building. What tools did the first humans need and what did they use for survival. What properties did they need their tools to have? - wood and plant products, animal products, bone, hair, stone.
Make a list of the needs of a tribe of hunter-gatherers in ancient times
Key words: hard, light, strong, sharp, heavy, rigid, waterproof, flexible.
Plan the design of a bow and arrow for hunting, using materials available
in ancient times.
" Bow - strong and flexible
If you were to design a bow and arrow using modern materials what would you use?
Discussion about the extraction of metals from rocks - Bronze age, Iron age (p52) and alloys.
Activity - student
Investigate the similarities and differences between wooden splints (or lolly sticks if possible), balsa wood, ebony (or similar) and similar sized clean strips of copper, zinc and lead.
Suggestions have a series of experiments around the room for the students to rotate and test the following:
" Hardness (scratch test, each trying to scratch the other)
Write-up - Criterion B - communication
Data collection - tabulate results
3.5 Investigating limestone
Limestone is one of the most important types of rock in the world. Ciudad Encantada in Cuenca, North and South Downs in the UK etc.
Cerne Abbas Giant is a similar carving in the South Downs
White rock often called chalk (not the same as blackboard chalk) chemical
name Calcium Carbonate.
" Investigate the change in mass when a piece of limestone is heated
Igneous, sedimentary and metamorphic rocks. Explain the formation of
each with examples and diagrams.
3.7 A very important mineral (Salt)
Where does salt come from?
Discuss methods of finding out if the distillate contains salt. Evaporate a little of the original solution in an evaporating basin and repeat using a sample of the distillate. Have a full scale distillation apparatus set up in the laboratory and demonstrate it at the end of the lesson. The students should be able to draw the apparatus in 2 dimensions with pencil and ruler and labels.
Activity One World
This activity is very important in the modern world as approximately half the worlds population does not have enough water for thier daily needs (see reference material ). I suggest a One-World approach researching various populations where water supply is either scarce, polluted or too salty or isn't controlled efficiently (monsoons). The students could prepare a poster presentation focussing on a particular country of their choice.
Round off by discussing the different methods available for water purification with the pros and cons of each one.
Copyright: 2003 Isis Publication