Chemistry reactions and energy

• Sodium hydrogencarbonate


  • Fizzes
  • Creates bubbles
  • Effervescence
• Substance produced is carbon dioxide
• Test for carbon dioxide

  1. Bubble it through limewater

  2. Turns cloudy
• Reaction of sodium hydrogencarbonate and hydrochloric acid

  1. Sodium hydrogencarbonate

  2. Hydrochloric acid

  3. Sodium chloride

  4. Carbon dioxide
• A fuel is a substance which reacts with oxygen to give out a large amount of energy
• Combustion


  The technical term for burning
• Fuels


  • Methane
  • Propane
  • Coal
• Experiment to identify products of combustion


  1. Blue flame

  2. Drops of liquid

  3. Bunsen burner with air hole open

  4. U-tube ice bath

  5. Limewater

  6. Pump to pass gas through limewater
• Ice condenses any water vapour to liquid water
• Anhydrous copper sulphate turns from white to blue if water is present
• Anhydrous cobalt chloride paper turns from blue to pink if water is present
• All fuels produce carbon dioxide and water when burned
• Equation for methane burning


  Methane + oxygen → carbon dioxide + water
• Hydrocarbon


  Contains carbon and hydrogen only
• Carbohydrate


  Contains carbon, hydrogen and oxygen
• Our bodies need energy to function, obtained from food by respiration
• Respiration


  Glucose + oxygen → carbon dioxide + water
• Photosynthesis


  Carbon dioxide + water → glucose + oxygen
• Chlorophyll is required as a catalyst in photosynthesis
• Reaction of hydrochloric acid and sodium hydroxide

  Hydrochloric acid + sodium hydroxide → sodium chloride + water
• Temperature rise means exothermic reaction
• Reaction of hydrochloric acid and magnesium

  Hydrochloric acid + magnesium → magnesium chloride + hydrogen
• Temperature rise means exothermic reaction