MYP 6 Science - Chemistry

MYP 6.1.1: Safety in the laboratory

Objectives

  • To introduce the students to a new and potentially hazardous environment and explain safe practice.

Introduction

Discuss the need for specialised apparatus for the handling of chemicals and materials.

Potential Chemical Hazards:

  • Toxic by skin absorption and inhalation.
  • Acute (immediate effect) poisons e.g. cyanide, chlorine gas
  • Chronic (accumulative effect) poisons e.g. lead and heavy metal compounds
  • Carcinogens (explain as chemicals whose effects may appear years later as cancer)
  • Corrosive
  • Skin irritants - allergens
  • Flammable liquids

Demonstrate some examples from the chemical store:

  • Toxic: Lead salts - show formation of lead iodide
  • Flammable: 5 drops cyclohexane on a watch glass and ignite using a splint
  • Corrosive: Piece of magnesium ribbon into 10cm3 sulphuric acid (pop gas).
  • Oxidant: Glycerine and potassium manganate(VII) - delay!
  • Explosive: Picric acid - no demo

Explain safe disposal - Environment!

Symbols used to convey information about chemicals

Toxic Harmful or irritant Flammable Oxidising (helps other things to burn)
 
Explosive Corrosive Environmental hazard  

Reference: http://www.itcilo.it/english/actrav/telearn/osh/ip/symbols.htm

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
  • Always take appropriate safety precautions (safety glasses, fume cupboard etc)
  • Always report and clean up spillages appropriately (certain materials need to be cleaned up in a specific way)
  • Always follow instructions
  • Never eat or drink in the laboratory
  • Wash hands after handling chemicals

Possible Class activity

Draw hazard symbols in exercise books and explain what each one means.


Resources

Spotlight Science 7: p4-5

 


 
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