Oxidation

• Oxidation

  Oxidation of an element occurs when the element losses electrons.
• Reduction

  Reduction of an element occurs when the element gains electrons.
• When does oxidation and reduction occur?

  At the same time
• What is the reducing agent

  The element that loses electrons.
• What is the Oxidizing agent?

  The element that gains electrons.
• What is Oxidation number?

  The oxidation number of an element is the charge an element has or appears to have
• What is the oxidation number of simple elements example Fe?

  0
• In the combined state what is the oxidation number of group 1 elements? Example- NaCL what is the value of Na?

  Group 1 elements have an oxidation number of +1 in their combined state.
• In the combined state what is the oxidation number of group 2 elements? Example- MgF2 what is the value of Mg?

  Group 2 elements have an oxidation number of +2 in their combined state.
• In simple ions (single element ions) what is the oxidation number of the ion equal to?

  In simple ions the oxidation number of the ion is equal to the charge of the ion
• Halogens (Group 7) in compounds have an oxidation number of what? And what is an exception to this rule?

  Halogens in compounds have an oxidation number of -1. However if the halogen is bonded to a more electronegative element oxidation number is +1.
• Oxygen usually has an oxidation number of what? And what is an exception to this rule?

  Oxygen has an oxidation number of -2. Except in the compound OF2 (oxygen difluoride) it is +2 because F is more electronegative than Oxygen.
• What is the oxidation number of oxygen in the peroxide ion?

  -1

  
• What is the oxidation number of H (Hydrogen) in compounds? What is an exception to this rule?

  Hydrogen has an oxidation number of +1 in its compounds except when it is combined to an element less electronegative than it because it is a hydride and has an oxidation number of -1.
• In complex ions where there is more than one element in the ion the oxidation number of the element must add up to?

  The charge of the ion.
• In neutral molecules the oxidation number must add up to what?


  The oxidation numbers must add up to zero.
• What is oxidation in terms of oxidation numbers?

  Oxidation is an increase in oxidation number.
• What is the use of hydrogen peroxide?

  Oxidize pigments in hair to make it blonde.
• What does sodium hypochlorite in household bleaches do?

  Oxidizes dyes in fabrics to become colourless.