1. 11.2 NOTES Fossil Fuels and Energy

2. Humans have used petroleum in small amounts for 5000 years
Only recently (1859) has consumption increased

3. Chem Quandry 1: Energy Tracing of a Paperclip
What general events must have occurred to produce the paper clip and delivery it to CHS?
Mine ore
Process ore
Form steel/aluminum
Draw into wire
Cut wire
Bend clips
Packaging
Transport to retailer
Transport to school
From where did the energy for each even come?
Petroleum, coal, wood (packaging), nitroglycerin (mining, TNT)
In your view, is the total cost of a box of paper clips related more to the materials used (the metals in the alloy) or the energy required?
The total cost is more related to the energy rather than the materials.

4. B.1 Energy and Fossil Fuels
Come from biomolecules of prehistoric plants and animals
Biomolecules  molecule that comes from living things
The energy in fossil fuels comes from the energy plants gain during photosynthesis

5. There are several different types, including petroleum, coal, and natural gas
Sometimes called buried sunshine
Plants originally got energy from the sun through the photosynthesis and the plants undergo changes underground
How are these fossil fuels formed?
Extreme pressure and heat; microbes also help the process

7. Potential energy Kinetic energy
Stored energy, energy of position (gravitational) or condition
Kinetic energy
Energy of motion

8. Forms of Kinetic Energy Forms of Potential Energy
Motion
Gravitational
Heat (Thermal)
Chemical
Sound
Stored Mechnical (springs, rubber bands)
Radiation
Nuclear
Electrical

9. Energy stored in chemical bonds, potential
Energy is released when bonds are formed.
Example Reaction:
CH4 + O2  CO2 + 2H2O + ENERGY!

10. Thermal energy
Heat energy
Endothermic changes
Need energy in order to occur – absorbs energy
All Bond breaking steps are endothermic
Energy is a reactant
Energy + AB  A + B
Exothermic reactions
Give off the energy until all energy is used up – releases energy
Product in the reaction
Occurs during the formation of bonds
X + Y  XY + Energy

11. If more energy is given off than absorbed, it is an exothermic reaction
If more energy is absorbed than given off, it is an endothermic reaction
Potential energy can be converted to kinetic energy
The energy in a reaction can be reversible
2H2 + O2  2H2O + Energy Exothermic
Energy + 2H2O  2H2 + O2 Endothermic

12. B.2 Energy Conversion
Energy goes through several conversions in order to be used. You can’t use coal directly to turn on a light.
Law of conservation of energy
Energy cannot be created or destroyed in a chemical, physical or mechanic process
“lost” energy is converted to thermal energy

13. B.4 Energy Efficiency
We need to reduce the number of energy conversions and increase the efficiency of the device
Each time energy is converted from one form to another, energy is lost in the form of heat
Many devices are less than 50% efficient
They can produce harmful byproducts
Energy is given off as heat that can’t do useful work

14. COMPLETE ACTIVITY!
We will go over it in a few…..