Chemistry In Industry (Cracking, Crude Oil, Polymers, Haber Process) Flashcards
What is cracking
Splitting up long chain hydrocarbons
Longer hydrocarbons have _________ boiling points and are _______ viscous. They are also thicker and __________ in colour
Higher
More
Darker
Why do we crack
Because demand for short chain hydrocarbons is much higher
Cracking:
Temperature:
Catalysts needed:
Temperature: 600-700C
Catalyst needed: Silica and alumina
What is crude oil
A mixture of hydrocarbons
From top to bottom: What are the fractions formed from crude oil
Refinery gases Gasoline Naphtha Kerosene Diesel Fuel oil Bitumen
How does fractional distillation of crude oil work
Oil is heated
Gases evaporate
When the temperature becomes lower than their boiling point, the gases condense
What is the purpose of bubble caps
To prevent liquids from running back down
As you go up, the fractions get:
_______ viscous
________ flammable
_________ boiling points
Less viscous
More flammable
Lower boiling points
Use of:
Refinery gases
Heating
Use of:
Gasoline
Fuel for cars
Use of:
Naphtha
Plastics
Use of:
Kerosene
Jet engines
Use of:
Diesel
Fuel for diesel engined cars, trucks etc.
Use of:
Fuel oil
Domestic central heating
Use of:
Bitumen
Road surfacing
What may incomplete combustion of fuel produce
Carbon monoxide
In car engines, the temperature is high enough for what to happen
Nitrogen and oxygen to react forming nitrogen oxides
Nitrogen oxides and sulfur dioxides are pollutant gases which contribute to what?
Acid rain
What is an addition polymer formed by
Many small molecules called monomers
What are the 2 types of polymer
Addition polymers
Condensation polymers
Under _______ pressure and a catalyst, alkenes will open up their double bonds and join together to form __________. What is this is known as
High
Polymers
Addition polymerisation
What is condensation polymerisation
When different types of polymer react together and bonds form between them, making polymer chains
For each new bond that forms in condensation polymerisation, a small molecule (e.g _______) is lost
Water
Name an example of a condensation polymer
Nylon
Name a use for poly(ethene)
Plastic bags
Name a use for poly(propene)
Carpets
Name a use for poly(chloroethene)
Clothes, pipes
What is a problem with polymers due their inertness
Since they are inert, they don’t react. They are hard to get rid of
It takes a very _______ time for polymers to biodegrade
Long
What does biodegrade mean
Be decomposed by bacteria
The haber process produces __________ which is used to make __________
Ammonia
Fertilisers
Which two elements are used to make ammonia
Nitrogen and Hydrogen
Where is nitrogen obtained from
The air
Where is hydrogen obtained from
Natural gas, or cracking
Conditions for haber process:
Temperature:
Pressure:
Catalyst:
Conditions for haber process:
Temperature: 450C
Pressure: 200atmospheres
Catalyst: Iron
Higher pressures favour the forward reaction, so the pressure is made as _______ as possible without making the plant too expensive to build
High
In the haber process, the forward reaction is ______thermic
Exothermic
What does increasing the temperature do to the equilibrium
Moves it the wrong way - Away from the ammonia and towards the N2 and H2
Why do we increase the temperature a bit even though increasing the temperature would move the equilibrium the wrong way,
Because increasing the temperature also increases the rate of reaction. 450C is a comprimise
The ammonia is formed as a _______
Gas
What happens when the ammonia cools in the condenser
It liquefies and is removed
What happens to the unused hydrogen and nitrogen
It is recycled so nothing is wasted
What can ammonia be used for
Fertilisers
Ammonia can be used to make nitric acid, what do you get if you react ammonia with nitric acid
Ammonium nitrate
Why is ammonium nitrate a particularly good fertiliser
Because it contains nitrogen from two sources
