Chemistry For Changing Times Chapter 15

Fossil Fuels

90% of energy in modern society (coal, petroleum, and natural gas)

Fuel Cell

A device in which fuel is oxidized into an electrochemical cell so as to produce electricity directly

Petroleum

A extremely complex, black, viscous liquid mixture of organic compounds. Most are hydrocarbons (alkanes, cycloalkanes, and aromatic compounds).

Entropy

A measure of the dispersal energy in a system. Example: the more the energy is spread out, the higher the entropy of the system and the less likely it is that this energy can be harnessed to do useful work.

Fuel

A substance that burns readily with the release of significant amounts of energy 1) Wood 2) Dung 3) Waterwheel 4) Windmill

Endothermic

Absorbs heat Example: melting ice

What is the primary element of coal?

Carbon

Exothermic

Chemical reactions that result in the release of heat from the system to the surroundings Example: freezing water

Where does coal come from?

Decomposed plants

Biomass

Dry-plant material (wood) can be burned directly or converted to liquid or gaseous fuels, but it requires much land area to produce and has very low over-all efficiency.

Potential Energy

Energy due to position or arrangement Example: water at the top of a dam has potential energy due to gravitational pull

Second Law of Thermodynamics

Energy flows from hot objects to cool objects.

Kinetic Energy

Energy of motion

Photovoltaic Cells

Made from elemental silicon, sunlight is converted directly to electricity through these devices

What technology is NOT used at all toady for the production of electricity?

Nuclear Fusion

Why is coal mainly carbon?

Plants are mainly cellulose, a compound of C, H, and O

Photosynthesis

Solar energy is absorbed by plants and used to produce glucose, and oxygen is generated.

First Law of Thermodynamics

States that energy can be neither created nor destroyed. Energy can be changed from one form to another however. This law is also called the law of conservation of energy.

What is the rate of using or producing energy, in units of J/second?

Watt