Voltaic Cells/Electrochemical Cells/Spontaneous Reactions

 Involve the conversion of chemical energy into electrical energy  Spontaneous reactions take place within the cells  A flow of electrons is produced that can be captured to power a device  We can use the activity series to see if our cell is operational Electrochemical Cells(Voltaic Cells)

 1. Electrode – Metal Surface that conducts electricity  This is the site of oxidation and reduction in the cell  2. Anode—Site of Oxidation (AN OX)  The anode loses mass, and provides the electrons for the power  This is the higher metal on Table J  The anode has a negative charge (Source of electrons) Parts of an Electrochemical Cell

 3. Cathode—Site of reduction within the voltaic cell  Gains mass during the reactions in the cell  Ions are reduced from the solution and attach themselves to the electrode in the cell  This is the lower metal on Table J  RED CATS  Cathode has a POSITIVE charge (Draws the electrons to it) Parts Continued

 4. Half-Cell—One half of an electrolytic cell set up  5. Salt-Bridge– device that allows for the movement of electrolyte ions  Connects the cells to each other to prevent the build up of charge  Without the salt-bride the charges build up in the cells and it stops working  YOU MUST ALWAYS HAVE A SALT BRIDGE Parts Continued

 Cell that requires the input of a current to get the reaction started  These are non-spontaneous because under normal conditions the reaction will not take place Nonspontaneous Cells: Electrolytic Cells

 1. NO Salt bridge  2. One Container  3. Non-spontaneous  4. Anode is Positive/Cathode is Negative  AN OX STILL EATS RED CATS!!!!!!!!!! 4 Differences Between Electrochemical and Electrolytic Cells

 1. Electrolysis---process where a current is used to initiate the reaction and separate compounds into elements  Can be used to isolate hydrogen and oxygen from water  Or to isolate a reactive metal (Sodium) from sodium chloride  2. Electroplating—process where a metal is coated with a different metal  Used for corrosion prevention or alloying Uses of Electrolytic Cells