C5: Chemical Changes

• Chemical change

  A process where substances react to form new substances with different properties
• Oxidation


  The gain of oxygen by a substance or the loss of electrons
• Reduction

  The loss of oxygen by a substance or the gain of electrons
• Redox reaction

  A reaction where both oxidation and reduction take place
• Reaction of a metal with oxygen

  Metal + Oxygen → Metal Oxide
• Determining reactivity of metals

  • Observing their reactions with water, acids, and oxygen
• Reactivity series

  A list of metals arranged in order of their reactivity from highest to lowest
• "Please Stop Calling Me A Careless Zebra Instead Try Learning How Copper Saves Gold"
• Reaction of a metal with hydrochloric acid

  Metal Chloride + Hydrogen
• Reaction of sodium with water

  2Na + 2H₂O → 2NaOH + H₂
• Extracting metals more reactive than carbon

  By electrolysis
• Blast furnace process

  The process of extracting iron
• Reaction of magnesium with hydrochloric acid

  Magnesium + Hydrochloric Acid → Magnesium Chloride + Hydrogen
• Displacement reaction

  A reaction where a more reactive metal displaces a less reactive metal from its compound
• Base

  A substance that neutralizes an acid to form a salt and water
• Alkali

  A base that dissolves in water to release hydroxide ions (OH⁻)
• Neutralization reaction

  Acid + Base → Salt + Water
• pH scale

  Used to measure how acidic or alkaline a solution is
• pH range

  • Acids: 0-6
  • Neutral: 7
  • Alkalis: 8-14
• Hydrogen gas test: using a lit splint, produces a 'pop' sound
• Electrolysis

  The process of using electricity to break down a compound into its elements
• Electrolyte

  A liquid or solution that conducts electricity
• Electrodes in electrolysis

  Anode (positive) and cathode (negative)
• Anode in electrolysis

  Oxidation (loss of electrons)
• Cathode in electrolysis

  Reduction (gain of electrons)