Comparison of a Button Cell to a Dry CellBy Elisha, Jeremy and Tom

Button Cell

Chemistry of the Button Cell

•Half Equations▫Cathode reactionAg2O (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)

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

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

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

Dry Cell/ Alkaline Cell

Chemistry

•Half Equations▫Cathode reaction▫MnO2(s) + 2H20(l) +2e Mn(OH)2 (s)+2OH

(aq) ▫Anode ReactionZn(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)

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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

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

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.