Experiment 14 OxidationReduction Reactions p' 183

1
Experiment 14 Oxidation-Reduction Reactions
p. 183

• To observe and predict products of
  oxidation-reduction reactions
• To determine the relative reactivity of a series
  of metallic elements

2
Introduction

• Reaction types
• Acid-base (exp. 13)
• Oxidation-reduction (redox) (exp 14)
• Single displacement
• Double displacement (metathesis) (exp 12)
• Decomposition

3
Introduction

• Redox reactions are often accompanied by
  spectacular color changes
• Fall leaves
• Rusting cars
• Explosives/fireworks
• Smog

4
Introduction

• In an acid-base reaction, protons (H) are
  transferred.
• In a redox reaction, electrons (e-) are
  transferred.
• Oxidation to lose electrons and thereby
  increase oxidation number.
• Zn(s) ? Zn2 (aq) 2e-
• Reduction to gain electrons and decrease
  oxidation number. Cu2(aq) 2e- ? Cu(s)

5
Introduction

• Electrons are neither products or reactants, they
  are shown in the reaction equations to balance
  the charge
• Zn(s) Cu2(aq) ? Zn2 (aq) Cu(s)
• Ox. Half-rxn Zn(s) ? Zn2 (aq) 2e-
• Red. Half-rxn Cu2(aq) 2e- ? Cu(s)

6
Introduction

• Refer to the reducing and oxidizing agents shown
  on p. 184.

7
Lab Notes

• A.1. Omit
• A.2. You will be working with strong acids, wear
  your gloves and be careful!
• Again, strong acid.
• C.1. Will not use Ni

8
Report Sheet

• Questions 4, 7, 8
• Hints for 8
• Think of what you studied in Part C.
• Redox reactions are an exchange of ?