The Finish Line is in site

1
The Finish Line is in site

• Electrochemistry

2
Balancing Redox Equations

• It is essential to write a correctly balanced
  equation that represents what happens in a
  chemical reaction
• We will be using the ½ reaction Method to balance
  redox reactions.

3
Using half-reactions

• A half-reaction is an equation showing just the
  oxidation or just the reduction that takes place
• They are then balanced separately, and finally
  combined

4
Using half-reactions

• Step 1 write unbalanced equation in ionic form
• Step 2 write separate half-reaction equations
  for oxidation and reduction
• Step 3 balance the atoms in the half-reactions
  (Except O and H)
• Step 4 Balance the O by adding water molecules
  to the other side

5
Using half-reactions

• Step 5 Balance the H atoms by adding H ions to
  the other side.
• Step 6 add enough electrons to one side of each
  half-reaction to balance the charges
• Step 7 multiply each half-reaction by a number
  to make the electrons equal in both
• Step 8 add the balanced half-reactions to show
  an overall equation

6
Using half-reactions In a basic solution

• Step 9 add enough OH- ions to equal the number
  of H ions present
• Step 10 form water molecules by combining OH-
  and H ions
• Step 11 clean-up the balanced equation by
  simplifying the water molecules if needed.