Chemistry chapter 1

• Chemistry


  A branch of science that studies the composition, structure, characteristics and interaction of matter
• Chemistry enables us to produce various useful chemicals in our daily life
• Alchemy


  The art of transforming common metals into gold and silver, and the production of elixir (a substance that prolongs life)
• Common chemicals in medicine

  • Propan-1-ol (rubbing alcohol) as antiseptic
  • Paracetamol, aspirin as analgesic to reduce pain
  • Gypsum (calcium sulfate) as plaster of Paris
• Common chemicals in food

  • Sodium bicarbonate used in baking powder
  • Acetic acid as vinegar
  • Sucrose as sugar
  • Sodium chloride as table salt
• Common chemicals in agriculture

  • Lime (calcium hydroxide) to neutralize acidic soil
  • Urea, nitrate salts, ammonium salts, potassium salts, phosphate salts as fertilizers
  • Copper(II) sulfate as fungicide
• Common chemicals in industries

  • Copper as wires
  • Ceramics
  • Synthetic polymers as building materials
  • Sulfuric acid to produce detergents, pigments and plastics
  • Ammonia to produce nitrogen fertilizers, as cooling agents in air conditioners
• Development of chemistry before 17th century

  • Man already knew how to extract metals, make glass and ceramics, ferment grapes into beer, extract medicine and perfumes from plants
• Development of chemistry in 17th century


  • Systematic investigation began, chemistry differentiated from alchemy, Robert Boyle introduced scientific method and earliest ideas about atoms, molecules and chemical reactions
• Development of chemistry in 18th century

  • Antoine Lavoisier introduced law of mass conservation and classification of elements
• Development of chemistry in 19th century

  • John Dalton introduced theory of atoms, Dmitri Mendeleev produced first periodic table, J.J. Thompson discovered electrons, Ernest Rutherford discovered radioactive sources
• Development of chemistry after 19th century

  • Fritz Haber introduced production of ammonia, Albert Einstein explained Brownian movement, James Chadwick discovered neutrons
• Examples of skilled workers in chemistry

  • Chemist
  • Pharmacist
  • Forensic expert
  • Biochemist
  • Chemical engineer
  • Cosmetologist
  • Food technologist
• Contribution of chemical technology in nanotechnology

  • Carbon nanotubes that are many times stronger than iron but lighter
  • Badminton rackets made from carbon nanotubes are lighter and stronger
• Contribution of chemical technology in cosmetics

  • Cosmetic products are prepared from chemicals
• Contribution of chemical technology in pharmaceuticals

  • Medicines are chemicals that are synthesized or chemically extracted from natural substances
• Contribution of chemical technology in green technology

  • Production of biodegradable plastics and paints with less volatile carbon compounds
• Contribution of chemical technology in biotechnology

  • Using living organisms to produce useful chemicals in medicine, agriculture and food
• Scientific investigation


  A systematic investigation done objectively using analytical and critical thinking
• Types of variables in an experiment

  • Manipulated variable (factor purposely changed)
  • Responding variable (factor that changes with manipulated variable)
  • Constant variable (factors kept constant)
• Steps in a scientific investigation

  1. Make observations

  2. Make an inference

  3. Identify the problem

  4. Make a suitable hypothesis

  5. Identify the variables

  6. Control the variables

  7. Plan and carry out an experiment

  8. Collect data objectively

  9. Interpret data

  10. Make a conclusion

  11. Write a report
• Self-protecting equipment


  Equipment used to protect individuals carrying out activities in a chemical laboratory
• Fume chamber


  Used to carry out experiments that release flammable or toxic vapors
• Safety shower


  Used to clean the body from harmful chemical spill
• Eye wash


  Used to clean the eyes from chemicals
• Fire extinguishers and fire blanket

  Used for extinguishing fire
• Steps in managing an accident in the laboratory

  1. Report any injury, broken glass, fire or chemical spill to the teacher immediately

  2. Use appropriate methods to clean up spills or broken apparatus
• Accident management for different types of accidents

  • Acid spill: Wash with lots of water, neutralize with sodium bicarbonate
  • Mercury spill: Ventilate, collect with mercury collector, store in closed bottle
  • Volatile/inflammable solvent spill: Wipe off with cloth, dispose cloth properly
  • Fire: Use fire extinguisher or sand, wrap victim in fire blanket, seek medical treatment for burns
• Storing of chemicals


  Proper storage methods for different types of chemicals to prevent hazards
• Storing of chemicals


  • Heavy metals in special containers with labels, away from heat
  • Toxic substances in special containers with labels, away from heat
  • Easily decomposed substances in dark bottles
  • Substances with pH<5 or >9 in special storage, locked
  • Reactive substances like sodium metal in paraffin oil
• Disposal of chemicals


  Proper disposal methods for different types of chemicals to prevent hazards
• Disposal of chemicals


  • Volatile substances in closed containers, away from heat and light
  • Heavy metals in plastic bags to evaporate, then dispose in special barrels
  • Toxic substances in plastic bags to evaporate, then dispose
  • Substances with pH<5 or >9 in closed containers, then dispose
  • Organic solvents and hydrocarbons in special glass/plastic containers