Redox Reactions

• What are redox reactions?

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

  Oxidation is the gaining of oxygen
• What does reduction mean in terms of oxygen?

  Reduction is the loss of oxygen
• What happens when aluminum reacts with oxygen?

  It forms aluminum oxide and is oxidized
• What mnemonic helps 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 does the term redox stand for?

  Reduction oxidation reactions
• What happens when magnesium reacts with dilute acid?

  Magnesium loses electrons and forms magnesium two plus ions
• What do hydrogen ions do in the reaction with magnesium?

  They gain electrons and become neutral hydrogen atoms
• What is a displacement reaction?

  A reaction where 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 in a reaction?

  Ions that do not change during the reaction
• How do we write ionic equations?

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

  To show the gain and loss of electrons for each element
• How do you balance charges in half equations?

  Add electrons to make charges equal on both sides
• What is the charge balance in the iron half equation?

  Left side has two plus, right side is neutral
• What should you check in half equations?

  That the overall charges on each side balance
• What happens if charges don't balance in half equations?

  You likely placed electrons on the wrong side