Redox Reactions

• What are the three common definitions of oxidation?

  Gain of oxygen, loss of hydrogen, loss of electrons
• What is reduction defined as in chemistry?

  Loss of oxygen, gain of hydrogen, gain of electrons
• What happens to carbon monoxide in the extraction of iron?

  Carbon monoxide is oxidised
• What is the oxidation reaction of ethanol to ethanal?

  C₂H₅OH → CH₃CHO
• What is the reduction reaction of ethanal back to ethanol?

  CH₃CHO → C₂H₅OH
• What happens to copper ions in the reaction with magnesium?

  Copper ions gain electrons and are reduced
• What is the oxidation reaction of magnesium in the reaction with copper oxide?

  Mg → Mg²⁺ + 2e^-
• What acronym helps remember oxidation and reduction definitions?

  Oil rig
• What occurs simultaneously in redox reactions?

  • Oxidation and reduction happen at the same time
  • Half equations represent oxidation or reduction
• What is an oxidising agent?

  A substance that oxidises something else
• What happens to the oxidising agent in a reaction?

  The oxidising agent is itself reduced
• What is a reducing agent?

  A substance that reduces something else
• What happens to the reducing agent in a reaction?

  The reducing agent is itself oxidised
• What is the oxidation state of an uncombined element?

  Always zero
• What is the oxidation state of elements bonded to identical atoms?

  Also zero
• What is the oxidation state of a simple monatomic ion?

  Same as its charge
• What is the oxidation state of vanadium in V²⁺?

  +2
• What is the oxidation state of vanadium in V³⁺?

  +3
• What is the oxidation state of vanadium in VO²⁺?

  +4
• What is the oxidation state of vanadium in VO²⁺ when it exists in +5 state?

  +5
• How do oxidation states work in compounds?

  • Each atom has its own oxidation state
  • The sum equals the overall oxidation state of the compound
  • Most electronegative element has a negative oxidation state
• What is the oxidation state of oxygen in a sulphate ion (SO₄^2-)?

  -2
• What is the oxidation state of sulphur in a sulphate ion (SO₄^2-)?

  +6
• Which element is the most electronegative in the periodic table?

  Fluorine
• What is the oxidation state of fluorine?

  -1
• What is the oxidation state of hydrogen?

  +1
• What are the common rules for oxidation states based on periodic table position?

  • Sodium (Na): Group 1, +1
  • Magnesium (Mg): Group 2, +2
  • Oxygen (O): Group 6, -2 (exceptions)
  • Hydrogen (H): Group 1, +1 (exceptions)
  • Fluorine (F): Group 7, -1
  • Chlorine (Cl): Group 7, -1 (exceptions)
• What is the oxidation state of hydrogen in hydrogen peroxide (H₂O₂)?

  +1
• What is the oxidation state of oxygen in hydrogen peroxide (H₂O₂)?

  -1
• How is the oxidation state of copper indicated in copper(II) sulphate?

  By roman numerals
• What is the oxidation state of copper in copper(II) sulphate?


  +2