C1 Oils, Earth And Armosphere

Question 0

How does cracking work?

Answer 0

It contains thermal decomposition.
The long chained hydrocarbon is vaporised.
This is then passed over a powered catalyst at a temperature of about 400-700 C
Aluminium oxide is the catalyst used.
The products are shorter alkanes and unsaturated alkenes.
THERE IS SUPER HEATED STEAM THERE AS WELL.

Question 1

What does cracking mean?

Answer 1

Splitting up long chained hydrocarbons and introducing a double bond.

Question 2

What is the feature of alkenes ?

Answer 2

They have a double bond between two of the carbon atoms.

They are unsaturated as they could make more bonds.

Question 3

What is the general formula for alkenes?

Answer 3

C”n”H”2n”

Question 4

What is a test for alkenes?

Answer 4

Add bromine water. If an alkane is present the double bond will break open and react with the bromine. It will turn from yellow to colourless.

Question 5

How can ethene be reacted with steam to produce ethanol?

Answer 5

Add the two together with a catalyst and ethanol is made. This is a hydration reaction.
It is a cheap and efficient process , but it depends on fossil fuels.
C”2”H”4” + H2O = C”2”H”5”OH.

Question 6

How can ethanol be produce from renewable resources?

Answer 6

Fermentation happens.
Yeast turns sugar into ethanol with CO2 as a by product.
A lower temperature and simpler equipment is needed.
It is also renewable.
It is cheap.
It is carbon neutral.
However it isn’t concentrated so it has to be distilled and purified.
C”6”H”12”O”6” (sugar) + yeast + water = CO2 and ethanol.
C”2”H”5”OH

Question 7

What are the basics of polymerisation?

Answer 7

Lots of small alkenes are joined together to form larger polymers.
Many ethane molecules can be joined together to produce poly(ethene).

Question 8

How can the reaction conditions of polymers create different properties?

Answer 8

Poly(ethene) made at 200C and 2000 atmospheres of pressure is flexible and has a low density.
But poly(ethene) made at 60C and a few atmospheres with a catalyst is rigid and dense.

Question 9

What can polymers be used for?

Answer 9

Light stretchy ones can make plastic bags. Elastic ones can make super stretchy LYCRA.
New uses are being developed like dental polymers for fillings and water proof coatings.

Question 10

How can we extract oils from plants?

Answer 10

Plant material can be crushed and pressed.
A centrifuge can be used as can solvents.
Distillation refines oil and removes water, solvents and impurites.

Question 11

Why are vegetable oils used?

Answer 11

They contain a lot of energy, vitamins and minerals and essential fatty acids.

Question 12

What are the benefits of oils in cooking?

Answer 12

They have a higher boiling point than water. This means they can be used to took things at higher temperatures and at faster speeds.
It increases the energy content.
Cooking with oil gives a different flavour. Also the oil”carries” the flavour as many flavour chemicals are soluble in water.

Question 13

How can vegetable oils bemused as to produce fuels?

Answer 13

Rapeseed and soybean oil can be turned into fuels.
This is because they contain a lot of energy.
Biodiesel comes from plant oil.

Question 14

What do oils and fats contain?

Answer 14

Long-chained molecules with lots of carbon atoms.

Question 15

What does monounsaturated and polyunsaturated mean?

Answer 15

The former, one double carbon bond. The latter , many double carbon bonds.

Question 16

How can unsaturated oils be hydrogenated?

Answer 16

React them with hydrogen at 60C with a nickel catalyst. This means the double bonds are broken open and the hydrogen joins up.

Question 17

Why are unsaturated oils hydrogenated?

Answer 17

It gives them a higher boiling point. This makes them good for spreading.
This is better than butter as they are cheaper a keep longer.
However they can contain lots of trans fats which are bad for you.

Question 18

What are the health problems with vegetable oils?

Answer 18

Saturated fats are worse for you as they increase cholesterol and the risk of heart disease.
Unsaturated fats are healthier but have trans fats so can also increase cholesterol.

Question 19

What are emulsions?

Answer 19

A mixture of one liquid suspended in droplets in another.

Question 20

What are properties and uses of emulsions?

Answer 20

They are thicker than the two liquids on their own.
They are used in food. Olive oil and vinegar can be mixed together and this coats salad better then on their own.
The more oil, the thicker it is.
Whipped cream also contains air.

Question 21

What do emulsifiers is do?

Answer 21

The help water and oil mix. They have a hydrophilic and a hydrophobic end. The two ends will stick to some oil and to some water.
These mean that droplets of oil are surrounded by the emulsifier and they are hydrophilic so the droplets can’t join.

Question 22

What ate the pros and cons of using emulsifies?

Answer 22

They give emulsions a longer shelf life.
They make food that is low in fat and has a good texture.
However some people are allergic to them.

Question 23

Why did Wegener believe in continental drift?

Answer 23

He found that there were similar fossils in Africa and South America.
He also noticed that the two continents could fit together.
He noticed matching layers of rock in the two places and fossils of tropical plants in the Antarctic.
In 1915 he said there was once a super continent called Pangaea. All the continents broke off from this and were still moving.

Question 24

Why wasn’t Wegener’s theory accepted ?

Answer 24

He said the movement came from the tides and the Earths rotation, but geologists said this was impossible.
He used inaccurate data and made inaccurate calculations on their speed.
He studied astronomy so didn’t know much about astronomy.
Went against religion.
No records of it.
Can’t be observed.

Question 25

Describe the structure of the Earth.

Answer 25

On the outside is the crust. 5-50 KM thin.
Below this is the mantle. It has the properties of a slid but can flow slowly.
Radioactive decay takes place here and creates heat and convection currents.
At the centre is a solid core and it is made of iron and nickel.

Question 26

Why do the tectonic plants move?

Answer 26

Convection currents in the mantle make them move a few centimetres every year. Sudden movements cause earthquakes.

Question 27

Why can’t scientists predict earthquakes and volcanic eruptions?

Answer 27

They move very slowly.

Sometimes there are mini quakes before but these can be a false alarm.

Question 28

What was the first phase of the atmosphere?

Answer 28

At first it was so hot everything boiled away.
Eventually things cooled down and a thin crust formed, but volcanoes kept erupting which meant a lot of gas was produced.
The first atmosphere was made of these gases. There was lots of CO2 with some water vapour, methane and ammonia.(NH”3”)
The oceans formed when the vapour condensed.

Question 29

Explain phase two of the atmosphere.

Answer 29

Green plants and algae evolved. They liked the CO2 atmosphere.
A lot of the CO2 was absorbed by the oceans. The early life photosynthesised and tuned CO2 to oxygen.
The first life became fossils fuels.
Bacteria turned ammonia into nitrogen.

Question 30

Explain phase three of the atmosphere.

Answer 30

The build up of oxygen killed off some organisms while other more complex ones evolved and flourished.
The oxygen created the ozone layer (O”3”). This blocked out harmful rays from the sun and enabled more complex life forms to form.

Question 31

How did life on earth start?

Answer 31

The primordial soup theory say billions of years ago the atmosphere was rich in nitrogen, hydrogen, ammonia and methane.
A lightning strike caused a chemical reaction between the gases creating amino acids which later combined to create organic matter in the soup.

Question 32

What is the Miller Urey experiment?

Answer 32

The correct gases were sealed up, heated and had a electric charge put through them for a week.
Amino acids were made but not as many as there were on Earth. This suggests the theory is on the right lines.

Question 33

How is air fractionally distilled?

Answer 33

It is filtered to remove air.
Co2 is removed to prevent it from freezing and blocking pipes.
Cooled to -200C turning it into a liquid.
During cooling, water vapour is condensed and removed.
The liquified air is the put in a fractional distillation column and heated.
Nitrogen goes to the top and oxygen and argon go to the bottom. These two will be separated with another column.

Question 34

How is the excess of CO2 affecting the oceans?

Answer 34

The oceans ate absorbing the CO2 but this means it gets too acidic. This is bad news for coral and shellfish. It also means it won’t be able to absorb any more CO2.

Question 35

What is locked up co2?

Answer 35

Co2 what was once in the earths early atmosphere that then became part of sedimentary rock or fossil fuels.

Question 36

Why does hardening oil make is less healthy?

Answer 36

No as the hydrogen adds to the unsaturated fat.

It makes is less unsaturated.

Question 37

Why did miller and Urey use the gases they did in their experiment?

Answer 37

The gases contain the atoms that are found in amino acids.

Question 38

Why does the miller Urey experiment only provide weak evidence for how amino acids formed?

Answer 38

Nobody knows what was in the first atmosphere.
There may have not been continuous lightning.
They only selected the gases needed to produce amino acids.

Question 39

If you have two liquids and they separate, why do they do it?

Answer 39

They don’t dissolve in one anoughter.

They is no emulsifier.