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Flashcards in C1f Deck (12):
1

What are the conditions needed for cracking?

-high temperature
-aluminium catalyst

2

Why is cracking done?

-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

What is cracking?

-splitting long alkane molecules into smaller alkane and alkene molecules
-thermal decomposition

4

How can oil cause political problems?

-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

How can oil cause environmental problems?

-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

What needs to be considered when picking the best fuels?

-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

What is complete complete combustion?

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

8

What are the benefits of complete combustion?

-clean and non-poisonous
-lots of energy produced

9

What is incomplete combustion?

-when there isn't enough oxygen
-carbon monoxide and carbon are produced
-smoky yellow flame

10

What are the disadvantages of incomplete combustion?

-less energy
-black carbon is sooty
-carbon monoxide is poisonous, colourless and odourless

11

What is the process of cracking?

-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

How to reduce the risk of carbon monoxide leaks?

-regularly service gas appliances