Chemistry - Fuels and Earth Science

What is fractional disillation?

Separating crude oil into different useful substances by evaporating it and cooling it up a tower

Why do different substances come out at different levels of a fractional distillation tower?

They have different boiling points

What is a complete combustion?

When hydrocarbons are burned and the only products are carbon dioxide and water

What is an incomplete combustion?

Hydrocarbon burns in a limited supply of oxygen

What determines a hydrocarbon’s properties?

Size

What are the properties of small hydrocarbons?

• Lower boiling point

• Easy to ignite

What is a pollutant?

Toxic substances that are produced when burning fossil fuels

What can be used as a clean, renewable fuel?

Hydrogen gas

What are the pros of using hydrogen gas as a fuel?

• Clean

• Renewable

What are the cons of using hydrogen gas as a fuel?

• Expensive

• Manufacturing it often uses energy from another source

• Hard to store

• Not widely available

Give examples of pollutants?

• Carbon monoxide

• Sulphur dioxide

• Oxides of nitrogen

What does sulphur dioxide cause?

Acid rain

What can oxides of nitrogen contribute to?

Photochemical smog

What is photochemical smog?

Air pollution that can cause breathing difficulties

What is cracking?

Splitting up a long chain of hydrocarbons

What is a theory about how the atmosphere might have evolved?

1. Volcanoes gave out steam and carbon dioxide

2. Plants evolved and produced oxygen

3. Ozone layer allows evolution of complex animals

How does human activity affect the earth?

As the population increases, carbon dioxide increases, as more are respiring. Therefore, the earth is getting warmer

How does the greenhouse effect make the earth warmer?

Sun gives out electromagnetic radiation, which is absorbed by the earth

What causes climate change?

Increasing greenhouse gases

How is methane produced?

Digestive processes of livestock

What does the increase of methane cause?

Global warming