1. Comparison of a Button Cell to a Dry Cell
By Elisha, Jeremy and Tom

2. Button Cell

3. Chemistry of the Button Cell
Half Equations
Cathode reaction
Ag2O (s) + H2O (l) + 2e- → 2Ag (s) + 2OH-
Anode Reaction
Zn (s) + 2OH- → ZnO (s) + H2O + 2e-
Full Equation
Zn (s) + Ag2O (s) → 2Ag (s) + ZnO (s)

4. Cost and Practicality Silver is an expensive metal
The production of the cell is therefore expensive
Non rechargeable
Small and light
Has a relatively long life span

5. Impact on Society
Due to its small size it has allowed the production of small electrical appliances
Due to its non toxic nature it has allowed for it to be used inside the body

6. Environmental Impacts
Due to its unrechargeable nature, it has to be discarded or recycled after only one use
Potassium hydroxide that is found within the cell is caustic (causing corrosion)
No highly toxic materials that will harm the environment

7. Dry Cell/ Alkaline Cell

8. Chemistry Half Equations - - - - Cathode reaction
MnO2(s) + 2H20(l) +2e  Mn(OH)2 (s)+2OH (aq)
Anode Reaction
Zn(s)+2OH (aq)  Zn (OH)2 (s) + 2e
Overall Reaction
MnO2(s) + 2H20(l) + Zn(s)+2OH(aq)Mn(OH)2 (s)+2OH (aq)+Zn (OH)2 (s) - - - -

9. Cost and Practicality Very cheap
Form of paste it is very convenient , being very transportable.
Small and easy to store and use
Maintains a steady voltage, therefore they are good for a range of electronic such as torches, walkman and toys.
Cannot be recharged
Short life
Cannot deliver a high current
Battery may leak

10. Impact on Society
Due to its low constant voltage it is used for common appliances such as torches, toys and portable radios/cds
Due to its mobility , portable items like flashlights could be used , therefore increasing the development of electrial equipments/ devices.
The popularity of batteries have increased

11. Environmental Impact
Small amounts of zinc are not problematic, however large amounts of zinc is a threat.
Manganese is also a heavy metal, dispose in large quantities are not beneficial for the environment.