1. Batteries By: Group H 2 0 Names of Team Members

2. Oxidation and Reduction Produces the electricity in batteries Involves the loss (oxidation) and gain (reduction) of electrons Called redox reactions, and occur simultaneously Zn (s) + Cu 2+  Zn 2+ + Cu (s) or, Zn (s) + Cu 2+ + 2e- Zn 2+ + 2e- + Cu (s)

3. Half-Reactions Called half reactions separately Oxidation half reaction: Zn (s)  Zn 2+ + 2e- Reduction half reaction: Cu 2+ + 2e-  Cu(s)

4. Oxidation and Reduction Substance that takes electron is called the oxidizing agent. Substance that gives up electron is called the reducing agent.

5. Electrochemical Cells Zinc and Copper can form and electrochemical cell Redox Reactions occur Zinc gives up 2 electrons to copper Zinc is oxidized into zinc ion Zn+2 Copper attaches to metal through reduction

6. Definitions Salt Bridge Electrochemical Cells Electrodes Electrolyte Discharge

7. Electrical Energy Obtained from any electrochemical cell Commercial electrochemical cells are batteries 2 types of batteries : Dry Cell, Alkaline

8. Dry Cell Batteries Commonly found in flashlights Filled with moist paste which contains manganese dioxide. Produces ammonia gases as they Shorter shelf life

9. Alkaline Batteries Also found in flashlights More expensive than dry cell batteries Contains zinc powder which reacts with metal strips which delivers power more quickly than dry cell batteries Do not produce ammonia gasses as they discharge Longer shelf life than dry cell.

10. Rechargeable Batteries The nicad battery is a rechargeable battery It is used in a variety of electronic equipment Named after it’s reactive materials nickel and cadmium. The discharge/recharge cycle can be repeated about a thousand times in a nicad battery.

11. Laptop Computer Batteries The lithium-ion battery is used in a laptop computer. Since it is made of lithium (which has low density) it makes the battery light. Lithium batteries are also the power source used in pacemakers.

12. Car Batteries Lead-Acid storage batteries are used as car batteries. They recharge automatically when the engine is running since electricity is produced by the generator driven by the car’s engine. They are also used to power golf carts, electric wheelchairs, and forklift trucks.

13. Electric Cars Use the same sort of lead-acid batteries that gasoline- powered cars use. Difficulties come across with the short range before the batteries need to be recharged. They are known as pollution free cars. There are several manufactures that offer hybrid electric cars.

14. Want Free Batteries? a. Rechargeable Battery b. Laptop Battery c. Electrode d. Electrolyte

15. References Chemistry in Your Life Book www.dictonary.com www.howstuffworks.com Handbook of Batteries and Fuel Cells Primary Batteries: recent advances www.energizer.com www.duracell.com