What is crude oil?
A finite, non renewable resource made from dead plants and animals.
Explain the method of separation of crude oil.
- Crude oil is heated strongly to evaporate it
-The column is hottest at the bottom and coldest at the top
-Vapours rise up the column and cool down - The vapours condense and become liquids when they reach the part of the column just below their boiling point
- The liquid condenses into a tray and is piped away
- The vapours with the lowest boiling points never condense and leave the top of the column as a mixture of gases
- Bitumen has the highest boiling point and leaves the bottom of the column as a hot liquid
Are fractions obtained by the separation of crude oil pure?
No
What are examples of small chain substances in crude oil?
gasoline, methane
What are examples of larger chain substances in crude oil
(In order from smallest chain:) Kerosene, Diesel, Fuel oil, Bitumen
Give a use for kerosene
Aircraft fuel
Give a use for fuel oil
power stations and ship fuel
Give a use for bitumen
roofing or roads
Why is Carbon Monoxide toxic to humans?
It displaces oxygen in the blood stream, depriving vital organs of oxygen
What problems does soot cause for humans?
asthma, heart diseases and cancer
What problems does sulphur dioxide cause?
Irritates eyes and restricts breathing. Acid rain
How are nitrogen oxides formed?
high temperatures cause nitrogen to react. (For example, a lightning bolt can split a triple bonded N2 molecule in the air. These quickly bond to surrounding oxygen molecules, forming nitrogen oxide)
Why are nitrogen oxides bad?
They can damage lungs and cause acid rain
What is cracking?
Breaking covalent bonds in larger chain hydrocarbon molecules to form smaller hydrocarbons
What does cracking always form?
An alkene and an alkane
How do hydrogen fuel cells work?
Hydrogen reacts with oxygen without burning. The energy released is used to generate electricity
What are the advantages of using hydrogen as fuel?
- Renewable
- Zero emission
- More effective
- More efficient
What are the disadvantages of using hydrogen as a fuel?
- Pure hydrogen is difficult and expensive to obtain
- Flammable
- Creation of pure hydrogen is usually powered by fossil fuels
Explain the development of Earth’s current atmosphere.
- The Earth’s early atmosphere was similar to Mars or Venus due to intense volcanic activity
- The atmosphere was mainly carbon dioxide
- The Earth cooled, causing water vapour to condense, forming the oceans. CO2 dissolved into the oceans, reducing it’s atmospheric levels
- Cyanobacteria in the ocean photosynthesise, decreasing CO2 further
- The atmosphere is now around 80% nitrogen, 20% oxygen, with trace amount of carbon dioxide
