There are three main types of batteries: 1) Primary cells, also known as batteries, undergo irreversible chemical reactions. 2) Secondary cells have chemical reactions that can be reversed through charging, allowing them to be recharged. 3) Flow batteries and fuel cells have materials that pass through the battery and undergo chemical reactions to produce electricity.

2. The Leclanch é (Dry) Cell Slide of 54

3. Dry Cell Slide of 54 Zn(s) -> Zn 2+ (aq) + 2 e - Oxidation : 2 MnO 2 (s) + H 2 O(l) + 2 e - -> Mn 2 O 3 (s) + 2 OH - Reduction: NH 4 + + OH - -> NH 3 (g) + H 2 O(l) Acid-base reaction: NH 3 + Zn 2+ (aq) + Cl - -> [Zn(NH 3 ) 2 ]Cl 2 (s) Precipitation reaction:

4. Alkaline Dry Cell Slide of 54 Zn 2+ (aq) + 2 OH - -> Zn (OH) 2 (s) Zn(s) -> Zn 2+ (aq) + 2 e - Oxidation reaction can be thought of in two steps: 2 MnO 2 (s) + H 2 O(l) + 2 e - -> Mn 2 O 3 (s) + 2 OH - Reduction: Zn (s) + 2 OH - -> Zn (OH) 2 (s) + 2 e -

6. Lead-Acid Battery Slide of 54 PbO 2 (s) + 3 H + (aq) + HSO 4 - (aq) + 2 e - -> PbSO 4 (s) + 2 H 2 O(l) Oxidation: Reduction: Pb (s) + HSO 4 - (aq) -> PbSO 4 (s) + H + (aq) + 2 e - PbO 2 (s) + Pb(s) + 2 H + (aq) + HSO 4 - (aq) -> 2 PbSO 4 (s) + 2 H 2 O(l) E° cell = E ° PbO 2 /PbSO 4 - E ° PbSO 4 /Pb = 1.74 V – (-0.28 V) = 2.02 V

7. The Silver-Zinc Cell: A Button Battery Slide of 54 Zn(s),ZnO(s)|KOH(sat’d)|Ag 2 O(s),Ag(s) Zn(s) + Ag 2 O(s) -> ZnO(s) + 2 Ag(s) E cell = 1.8 V

8. The Nickel-Cadmium Cell Slide of 54 Cd(s) + 2 NiO(OH)(s) + 2 H 2 O(L) -> 2 Ni(OH) 2 (s) + Cd(OH) 2 (s)

9. 20-7 Electrolysis: Causing Non-spontaneous Reactions to Occur Slide of 54 Galvanic Cell: Zn(s) + Cu 2+ (aq) -> Zn 2+ (aq) + Cu(s) E O 2 /OH - = 1.103 V Electolytic Cell: Zn 2+ (aq) + Cu(s) -> Zn(s) + Cu 2+ (aq) E O 2 /OH - = -1.103 V

12. Quantitative Aspects of Electrolysis Slide of 54 1 mol e - = 96485 C Charge (C) = current (C/s)  time (s) n e - = I  t F