REDOX

• REDOX


  Stands for reduction-oxidation.

  • It is when reduction AND oxidation occur in the same reaction.
  • These reactions are all about the transfer of ELECTRONS between substances:
  • OXIDATION is where a substance LOSES electrons and gain of oxygen.
  • REDUCTION is where a substance GAINS electrons and lose of oxygen.
• OIL RIG


  Oxidation

  Is

  Loss

  • this us what happens to electrons during redox reactions.

  Reduction

  Is

  Gain
• Displacement Reactions:


  examples of REDOX REACTIONS:

  • This occurs when a  MORE REACTIVE METAL replaces a LESS reactive METAL in a compound.
• For example; Zinc is placed in a Copper Sulfate solution:

  • Zinc is HIGHER in the reactivity series, so it REPLACES copper to form ZINC SULFATE.


  Symbol Equation:

  • Zn + CuSO4 -> ZnSO4 + Cu

  Ionic Equation:

  • $Zn\:+$$\:Cu^{2+}+$$SO^{2-}4\:->\:Zn^{2+}+$$\:SO^{2-}4\:+$$Cu$

  The element Zn turns into Zn2+

  • Zinc LOST TWO ELECTRONS , to get a charge of +2.
  • Zinc has been OXIDISED.

  The ion Cu2+ turns into Cu:

  • Cu2+ GAINED two electrons.
  • Copper has been REDUCED.
• Half Equations


  shows the ELECTRON TRANSFERS within an ionic equation.

  Electrons in half equations are represented as an e-.

  • The REDUCTION half equation:
  • Shows the element that GAINS electrons.
  • Electrons here are written on the REACTANTS side
  • (left hand side).
  • The OXIDATION half equation:
  • Shows the element that LOSES electrons.
  • Electrons here are written on the PRODUCTS side
  • (right hand side).

  
• REDOX reactions don't happen by themselves, both takes place at the same time:


  Magnesium atoms would lose two electrons and be oxidized - forming magnesium 2+ ions.

  • while the hydrogen ions will gain those electrons and be reduced to neutral hydrogen atoms in the form of hydrogen gas

  Word Equation:

  • Magnesium + Dilute Acid -> Oxidised magnesium + Hydrogen gas

  Symbol Equation:

  • $Mg+$$2H^+$$->\:Mg^{2+}+$$H_2$