Oxidation and reduction

• What is oxidation defined as?

  Loss of electrons
• What is reduction defined as?

  Gain of electrons
• Why are oxidation and reduction important in chemistry?

  They are critical to understanding chemical reactions
• What mnemonic helps remember oxidation and reduction definitions?

  Oil rig
• What does 'oil rig' stand for?

  Oxidation is loss, reduction is gain
• What are half equations in redox reactions?

  • Show changes in oxidation states
  • Illustrate electron transfer
  • Example: Magnesium atom to magnesium ion (oxidation)
  • Example: Sulfur atom to sulfide ion (reduction)
• How does a magnesium atom illustrate oxidation?

  By releasing electrons to form a magnesium ion
• How does a sulfur atom illustrate reduction?

  By gaining electrons to form a sulfide ion
• How can you identify oxidation and reduction in chemical equations?

  • Analyze oxidation states of elements
  • Determine which elements are oxidized
  • Determine which elements are reduced
  • Example: Displacement reaction between zinc and copper sulfate
• What is the purpose of analyzing oxidation states in reactions?

  To determine which elements are oxidized and reduced