Rates of reaction (chp.21)

• The rate of reaction is the change in concentration of a reactant (or product) per unit time. They end up at the same point

  Average rate = change(product)/ time taken
• Factors affecting the rate of reaction

  • Type of particles

  a.liquids and gases react more quickly than solids

  b.some chemicals are more reactive than others

  • Particle size/surface area

  Smaller particles react more quickly than larger particles

  • Concentration

  More concentrated solutions react more quickly

  • Temperature

  Warmer systems produce quicker reactions

  • Catalysts

  -Catalysts are chemicals that speed up (or slow down) the rate of a chemical reaction without being used up in the reaction

  -adding catalysts usually speeds up the reaction

  -enzymes are organic catalysts
• Experiment to make oxygen gas

  A small amount of manganese oxide is put in the bottom of the beaker, and at least enough hydrogen peroxide solution is poured down the thistle funnel to cover the bottom of the funnel. The Oxygen is sent through a glass tubing into a graduated cylinder. There is rapid fizzing as oxygen is produced, and this can be collected over water.

  A) hydrogen peroxide

  B) oxygen gas

  C) water trough

  D) magnese

  E) beaker

  F) graduated cylinder

  G) glass tubing

  
• test for oxygen


  relights glowing splint
• test for carbon dioxide


  turns limewater milky
• test for hydrogen


  burns with a pop
• Experiment for Hydrogen

  A) graduated cylinder

  B) Magnesium

  C) HCL

  D) Water

  E) basin

  F) Hydrogen

  
• Experiment for Carbon Dioxide

  A) glass tubing

  B) water

  C) Carbon Dioxide

  D) graduated cylinder

  E) trough

  F) beehive shelf

  G) calcium carbonate

  H) hydrocholric acid

  I) funnet

  J) conical flask