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Flashcards in C1f Deck (12)
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1
Q

What are the conditions needed for cracking?

A
  • high temperature

- aluminium catalyst

2
Q

Why is cracking done?

A
  • to help match supply and demand
  • there is a higher supply of bigger hydrocarbons in crude oil than the demand for them
  • so they are cracked into smaller hydrocarbons to meet the demand for them, as the original supply was less
3
Q

What is cracking?

A
  • splitting long alkane molecules into smaller alkane and alkene molecules
  • thermal decomposition
4
Q

How can oil cause political problems?

A
  • prices rise as stocks are used up, countries with big stops may start keeping more for themselves instead of selling
  • countries with most oil and natural gas will have power over other countries. They can choose who and who not they supply to, inciting political conflict and even war
  • harder for countries without lots of oil to get a hold of it, we may depend on politically unstable countries and our supply could be cut off at any time
5
Q

How can oil cause environmental problems?

A
  • oil tankers crashes, oil floats on water and spreads out by the waves and tides into a big oil slick
  • oil covers sea birds’ feathers, stopping them being waterproof, water soaks into feathers and they die of cold (also, birds can’t fly with oil matted wings)
  • detergents used to clean oil slicks break oil into droplets and make it easier to disperse (some harm wild life, can be toxic to marine creatures like fish and shellfish)
6
Q

What needs to be considered when picking the best fuels?

A
  • energy value
  • availability
  • storage (if flamable or explosive it needs to be stored safely)
  • cost
  • toxicity
  • ease of use (whether is lights easily and or move it safely)
  • pollution
7
Q

What is complete complete combustion?

A
  • when there is plenty oxygen
  • complete combustion of any hydrocarbon will produce only carbon dioxide and water
  • has a blue flame
8
Q

What are the benefits of complete combustion?

A
  • clean and non-poisonous

- lots of energy produced

9
Q

What is incomplete combustion?

A
  • when there isn’t enough oxygen
  • carbon monoxide and carbon are produced
  • smoky yellow flame
10
Q

What are the disadvantages of incomplete combustion?

A
  • less energy
  • black carbon is sooty
  • carbon monoxide is poisonous, colourless and odourless
11
Q

What is the process of cracking?

A
  • vapourised hydrocarbons pass over a powdered catalyst at 400C-700C
  • aluminium oxide is the catalyst
  • the long chains split on the surface of bits of catalyst
12
Q

How to reduce the risk of carbon monoxide leaks?

A

-regularly service gas appliances