Gen-Chem 2

• Oxidation

  The addition of oxygen/ electronegative element to a substance or removal of hydrogen / electropositive element from a substance
• Reduction

  The removal of oxygen / electronegative element from a substance or addition of hydrogen / electropositive element to a substance
• In order to convert free elements into an ion the atom must gain or lose electrons
• Reactions where electrons are transferred from one atom to another are redox reactions
• Atoms that lose electrons

  Are being oxidized
• Atoms that gain electrons

  Are being reduced
• Oxidants


  Reagents which increase the oxidation number of an element of a given substance
• Reductants


  Reagents which lower the oxidation number of a given element
• Electrochemistry


  Deals with oxidation-reduction reactions that either produce or utilize electrical energy and electrochemical reactions that take place in cells
• Each cell


  • Has two electrodes, conductors through which electrons enter or leave the cell
• Oxidation


  Occurs when an atom's oxidation state increases during a reaction
• Reduction


  Occurs when an atom's oxidation state decreases during a reaction
• Reactions that are energetically favorable


  Are said to be spontaneous
• Oxidation involves the loss of 2 electrons
• Relative reactivity of metals


  Can be used to determine if some redox reactions are spontaneous
• Electrolytes


  Substances which when dissolved in water, break up into cations and anions
• Types of electrolytes

  • Strong electrolytes
  • Weak electrolytes
  • Non-electrolytes
• Batteries


  Produce electricity through a chemical reaction between the metals and the electrolyte, which frees more electrons in one metal than the other, developing a positive and negative charge