Redox reactions

• What are redox reactions?

  Reactions where oxidation and reduction occur simultaneously
• What does oxidation mean in terms of oxygen?

  Gaining of oxygen
• What does reduction mean in terms of oxygen?

  Loss of oxygen
• What happens when aluminum reacts with oxygen?

  It forms aluminum oxide and is oxidized
• What is the mnemonic used to remember oxidation and reduction?

  Oil rig: Oxidation is loss, Reduction is gain
• What happens to a magnesium atom that loses two electrons?

  It becomes a magnesium two plus ion and is oxidized
• Why do redox reactions occur simultaneously?

  One substance loses electrons while another gains them
• What is the representation of an acid in reactions?

  H plus ions
• What happens when magnesium reacts with dilute acid?

  Magnesium loses electrons and forms magnesium two plus ions
• What do hydrogen ions become when they gain electrons?

  Neutral hydrogen atoms in the form of gas
• What is a displacement reaction?

  A more reactive metal displaces a less reactive one
• What happens when calcium is added to iron sulfate?

  Calcium displaces iron to form calcium sulfate
• What are spectator ions?

  Particles that do not change in the reaction
• How do we write ionic equations?

  By showing only the particles that change
• What is the purpose of half equations?

  To show the gain and loss of electrons
• How do you write a half equation for calcium?

  Neutral calcium atom forms calcium two plus ion
• What do you add to balance the charges in half equations?

  Electrons
• How do you check if charges balance in half equations?

  Ensure overall charge on each side is equal
• What happens if charges do not balance in half equations?

  You likely placed electrons on the wrong side
• What are the key components of redox reactions?

  • Oxidation: loss of electrons
  • Reduction: gain of electrons
  • Occur simultaneously
  • Involve electron transfer
• What are the steps to write ionic equations?

  1. Identify reactants and products
  2. Remove spectator ions
  3. Show only changing particles
• What is the reactivity series in displacement reactions?

  • Ranks metals by reactivity
  • More reactive metals displace less reactive ones
  • Used to predict reaction outcomes
• What is the significance of half equations in redox reactions?

  • Show individual electron transfer
  • Clarify oxidation and reduction processes
  • Help balance overall reactions