C1

Front 1

What is crude oil and how is it formed?

Back 1

Crude oil is a fossil fuel. It was formed from living things that lived in the sea millions of years ago. these became buried deep in the seabed , after they died. Chemical reactions happened that eventually turned them into crude oil. It is non renewable, they are finite resources.

Front 2

Separating crude oil

Back 2

1)The different compounds in crude oil are seperated by fractional distillation.

2)The crude oil is heated until most of it has turned into gas

3)The gases enter a fractionating column, apart from the liquid bitumen which drains out at the bottom

4)In the column there is a temperature gradient, hot at the bottom and cold at the top.

5)Longer hydrocarbons have higher boiling points. they turn into liquids and drain out early on.

6)The shorter hydrocarbons have lower boiling points they turn into liquid and run out much later on, where it is cooler.

7)You end up with crude oil separated out into separate fractions. Each fraction contains a mixture of hydrocarbons with similar boiling points.

Front 3

Covalent bonds

Back 3

The atoms in hydrocarbon molecules are joined together with covalent bonds.

Front 4

Intermolecular forces

Back 4

The covalent bonds holding the atoms in hydrocarbon atoms are much stronger than intermolecular forces that attract hydrocarbon molecules together the se forces are broken when crude oil is boiled, not the covalent bonds. this causes the hydrocarbon molecules to separate from each other when they are turned into a gas.

Front 5

Properties of hydrocarbons as the hydrocarbon chains get longer

Back 5

The boiling point increases

It gets less flammable

It gets more viscous (does not flow as easily)

It gets less volatile (doest evaporate as easily)

Hydrocarbons with smallest molecules are gases and those with largest molecules are solids.

Front 6

why do bigger hydrocarbon molecules have a high boiling point?

Back 6

the intermolecular forces are much stronger, so more energy is needed to overcome the attraction.

Front 7

Other problems with crude oil, environmental?

Back 7

Oil tanker crashes can lead to huge amounts of crude oil being released into the sea, the oil floats on water and the action waves spreads it out into the big oil slicks.

Oil then covers the sea birds feathers, and stops them from being waterproof, they will not be able to fly plus they will die from the cold water.

detergent are often used to clean oil slicks, they break the oil into tiny droplets, which makes it easier to dispose of. however it can still damage wildlife, as they can be toxic.`

Front 8

Political issues with crude oil?

Back 8

As stocks of ol get used up, the price of oil will increase, so plastics and fuels will get more expensive. Countries with big stocks can just start to keep it, than selling it.

The countries with more oil have more power, can lead onto war.

It will be harder for countries with less oil to get hold of it, so we have to supply from politically unstable countries and we can be cut of at any time.

Front 9

What is the point of cracking?

Back 9

Cracking is a chemical process converts large hydrocarbon molecules into smaller more useful hydrocarbon molecules. Turns long alkane molecules into smaller alkane and alkene molecules. thermal decompositon.

Front 10

what does cracking involve?

Back 10

It needs high temp and a catalyst, it involves heating the oil fractions to a high temperature and then passing it over a catalyst.

1)vaporised hydrocarbons are passed along the powdered catalyst at about 400-700 degrees.

2)Aluminium oxide is the catalyst, the long chain hydrocarbon molecules split or crack on the surface of the bits of catalyst.

Front 11

What is a fuel?

Back 11

A fuel is a substance that reacts with oxygen to release useful energy. this is mostly heat energy.

Front 12

Complete combustion

Back 12

If there is plentiful supply of oxygen complete combustion happens. the products are not poisonous:

the carbon reacts with oxygen: carbon dioxide

the hydrogen reacts with oxygen produces water.

hydrocarbon + oxygen → carbon dioxide + water (+energy).

Many gas heaters release these waste products into the room which is okay, as long as the heater is working properly and the room is well ventilated. Complete combustion releases a lot of energy. clean blue flame.

CH4 + 2O2 → CO2 + 2H2O (Methane)

Front 13

Experiment to check for complete combustion?

Back 13

The water pump draws up gasses from the burning candle through the water collects in the U tube, you can check its water by checking its boiling point. also the lime water will go milky - carbon dioxide. the apparatus will turn hot, energy.

Front 14

when does incomplete combustion happen?

Back 14

When there is a shhortage of air, therefore oxygen.This sort of combustion gives off carbon monoxideand carbon as waste products, yellow flame. the carbon monoxide is colourless, odourless and poisonous it is very dangerous, no one notices it. this is why gas appliances have to be serviced regularly, checked to make sure they are getting enough oxygen. Helps appliances release more energy and less soot produced from carbon (sooty marks).

hydrocarbon + oxygen → carbon monoxide + carbon + water

C2H6 + 2O2 → CO + C + 3H2O

Front 15

Factors to when choosing the right fuel?

Back 15

Energy value, the amount of energy available.

availability of the fuel

storage is the fuel flammable

toxicity harmful fumes?

Ease of use , can you move it easily or not?

pollution levels.

Front 16

The Earths atmosphere?

Back 16

mixture of gases surrounding the planet. The Earths gravity stops these gases escaping into space. the lower part of the atmosphere is what we breathe.

Front 17

Phase 1 of how the atmosphere was formed?

Back 17

Volcanoes gave out steam and carbon dioxide. The Earth atmosphere was originally molten for many years and any sort of atmosphere formed was burned away. eventually it coloed and a thin crust formed, but volcanoes get erupting releasing gases from inside the earth. This released carbon dioxide, steam and ammonia. when things settled down the early atmosphere was carbon dioxide and water vapour (water vapour condensed to form oceans)

Front 18

Phase 2 Green plants evolved and produced oxygen

Back 18

a lot of the early carbon dioxide dissolved in the oceans, green plants evolved over most of the Earth, as they photosynthesised they removed carbon dioxide and produced oxygen. Oxygen levels increased and carbon dioxide got locked up in fossil fuels and sedimentary rocks. Nitrogen was put into the atmosphere in two ways , ammonia reacted with oxygen, and by denitrfying bacteria. Nitrogen isn't very reactive, its levels increased but didn't get broken down.

Front 19

Phase 3 - ozone layer was formed which allowed the evolution of complex animals

Back 19

The build up of oxygen killed of early organisms that couldn't tolerate it. But it did allow the evolution of more complex organisms that made use of oxygen. the oxygen also created the ozone layer which blocked UV rays allowing organisms to develop.

Front 20

Percentage of gases in atmosphere?

Back 20

nitrogen 78%

oxygen 21%

Carbon dioxde 0.04%

Front 21

Describe the carbon cycle?

Back 21

Carbon is continuously recycled, carbon is key to the greenhouse effect, it exists in the atmosphere are carbon dioxide gas, and it is also present in many other greenhouse gases like methane. Carbon on Earth moves in one great cycle.

Front 22

What processes add carbon to the atmosphere?

Back 22

Respiration, combustion and decay of dead plants and animals, they also remove oxygen.

Front 23

What processes removes carbon from the atmosphere?

Back 23

Photosynthesis adds oxygen into the atmosphere and removes carbon, these processes balance out.

Front 24

why dont these processes balance out though?

Back 24

humans have affected the natural carbon cycle, which has affected the balance of gases in the atmosphere.