Fuels

What is a fuel?

• A substance that burns in oxygen to produce heat.

Fire Triangle

• Three conditions need for fire:

1) Fuel

2) Heat

3) Oxygen

Fire extinguishers

Fire blanket

Fossil Fuels

• Formed from the remains of organisms that lived millions of years ago.

Fossil Fuels

What are hydrocarbons?

Compounds made up from hydrogen and carbon.

Example: Methane (CH4)

To examine the products of combustion of a hydrocarbon

What are the products of combustion of a hydrocarbon?

• When a hydrocarbon is burned, water and carbon dioxide are produced.

How do you test for these products?

• Cobalt chloride paper changes from blue to pink in the presence of water

• Limewater turns a milky colour in the presence of carbon dioxide.

The greenhouse effect

• Heat is trapped by earth’s atmosphere.

• With increased levels of carbon dioxide released more and more heat is being trapped leading to global warming.

• Burning fossil fuels releases more carbon dioxide.

The Greenhouse Effect

Acid rain

• Most rain is slightly acidic.

• Carbon dioxide dissolves in water in the atmosphere to form carbonic acid (pH 5.5)

• Acid rain is becoming stronger due to burning more fossil fuels and more exhaust fumes being released (sulfuric acid and nitric acid)

Acid rain formation

Problems with acid rain

Can poison fish

Attacks buildings

Kills trees

Reducing the effects of acid rain:

• Decreasing the use of fossil fuels

• Using alternative energy sources (wind and solar energy)

• Fitting catalytic converters in cars to remove pollutants.

• Planting trees to absorb more carbon dioxide from the atmosphere.

Future impact of global warming ???