Crude Oil

Question 1

Crude oil is a ………… of hydrocarbons

Answer 1

Mixture

Question 2

What is a mixture?

Answer 2

A mixture consist of two (or more) elements/compounds that aren’t chemically bonded together

Question 3

Since there are no chemical bonds between the different parts of the mixture that means….

Answer 3

The different hydrocarbon molecules aren’t chemically bonded together so they keep all of their original properties (melting and boiling points)

Question 4

Are crude oils mostly alkanes?

Answer 4

Yes

Question 5

What are alkanes?

Answer 5

Alkanes are made up of chains of carbon atoms surrounded by hydrogen atoms
~ carbon atoms form 4 bonds
~ hydrogen atoms form 1 bond

Question 6

What is the formula for alkanes?

Answer 6

Cn H2n+2

Question 7

If methane has 1 Carbon atom how many hydrogen atoms does it have?

Answer 7

C1 H(2x1+2) = 4 hydrogen atoms

Question 8

The shorter the molecules in crude oil, the more….

Answer 8

Runny the hydrocarbon is ~ the less gloopy it is

Question 9

The shorter the molecules, the more….

Answer 9

Volatile they are (e.g. They turn into a gas at a lower temperature)
So the shorter the molecules the lower the temp at which that fraction vaporises
The lower its boiling point

Question 10

The shorter the molecules, the more….

Answer 10

Flammable it is

Question 11

Why is crude oil BAD for the environment?

Answer 11

~ oil spills can occur, as the oil is being transported from tanker - birds get covered and get poisoned, whales get poisoned too
~ because you have to burn oil to released the energy… This causes global warming, acid rain and global dimming

Question 12

You can reduce acid rain by?

Answer 12

Removing the sulfur emissions, before he fuel is burned. Of course this costs more and takes more energy

Question 13

What is global dimming?

Answer 13

• scientists have found some areas of the world nearly 25% LESS SUNLIGHT has been reaching the surface compared to 50 years ago!

Question 14

What causes global dimming?

Answer 14

Particles of soot and ash they get produced when fossil fuels burn, reflect he sunlight back into space

Question 15

What is ethanol?

Answer 15

It can be produced from plant material, known as a biofuel

It is made by fermentation of plants and is used to power cars

Question 16

What are the pros and cons about ethanol?

Answer 16

Pros: the Co2 released when the plant is burned is carbon neutral. The only other product is water

Cons: engines have to be converted before they work with ethanol fuels. It isn’t widely available
Farmers may switch from growing crops to growing ethanol crops - making food prices increase

Question 17

What is biodiesel?

Answer 17

Another type of biofuel. It can be produced from vegetable oils (rapeseed oil)
Biodiesel can be mixed with ordinary diesel do run a Diesel engine

Question 18

What are the pros and cons of biodiesel?

Answer 18

Pros: it is carbon neutral and engines don’t need to be converted. It produces less sulfur dioxide than ordinary diesel

Cons: enough can’t be made to completely replace diesel as it is expensive to make
It could also increase food prices

Question 19

What is hydrogen gas?

Answer 19

It can be used to power vehicles

~ you get the hydrogen from the electrolysis of water

Question 20

What are the pros and cons of hydrogen gas?

Answer 20

Pros: hydrogen combines with oxygen in the air to only form water - it is very clean

Cons: you need a special, expensive engine and hydrogen isn’t widely available and hydrogen is hard to store