Oxidation, Reduction, Redox

• What is the oxidation number of nitrogen in NH3?

  -3
• What is the total oxidation number in a neutral compound?

  It equals 0
• What is the oxidation state of an uncombined element?

  0
• What is the oxidation state of sodium (Na) uncombined with anything else

  0
• What is the oxidation state of chlorine in a simple ion?

  -1
• How do you find the overall charge of a compound with multiple atoms?

  Add up the individual oxidation numbers
• What is the oxidation state of oxygen in most compounds?

  -2
• When does oxygen have an oxidation state of -1?

  When combined with fluorine or in peroxides (H2O2)
• What is the oxidation state of hydrogen in metal hydrides?

  -1
• What is the oxidation state of fluorine in compounds?

  -1
• What is the oxidation state of chlorine when combined with fluorine or oxygen?

  +1
• What is the oxidation state of Group 1 elements?

  +1
• What is the oxidation state of Group 2 elements?

  +2
• What happens to the oxidation number during oxidation?

  It increases
• What happens to the oxidation number during reduction?

  It decreases
• What does OILRIG stand for?

  Oxidation Is Loss, Reduction Is Gain
• What is an oxidizing agent?

  It gains electrons
• What is a reducing agent?

  It donates electrons
• What are the rules for balancing half equations?

  • Species : Balance atoms other than O or H
  • Oxygen : Balance O using H₂O
  • Hydrogen : Balance H using H⁺
  • Charge :Balance charge using e⁻
• How do you combine half equations to form an overall equation?

  • Multiply half equations to equalize electrons
  • Overall equations do not include electrons
• Oxidation number of hydrogen

  +1
• Oxidation number of halides

  -1