Industrial processes Flashcards
Raw materials needed for Haber Process
- nitrogen
- hydrogen
Where is the nitrogen obtained from?
air
Where is the hydrogen obtained from?
- natural gas
- cracking hydrocarbons
What temperature is used for Haber Process?
450 oc
Why is this temperature used for the Haber process?
it is a COMPROMISE TEMPERATURE - favours low temperature but too low would be to slow to produce ammonia
What pressure is used for the Haber Process?
200atm
Why is this pressure used for the Haber process?
it is a COMPROMISE PRESSURE - favours high pressure but over 200atm would be too expensive
What catalyst is used for the Haber Process?
iron
What is the volume proportion of nitrogen to hydrogen?
1:3
What type of reaction is making ammonia?
reversible reaction
How is the ammonia separated from the mixture?
- mixture leaves reaction vessel and cools
- ammonia liquefies and is tapped off
Uses of ammonia
- fertilisers
- nitric acid
- nylon
Raw materials needed for Contact Process
- sulphur
- oxygen
Where is the sulphur obtained from?
iron pyrite
Where is the oxygen obtained from?
excess air
What temperature is used for Contact Process?
450c
Why is this temperature used for the Contact process?
it is a COMPROMISE TEMPERATURE - low temperature gives high conversion but not too low to slow down the reaction
What pressure is used for Contact Process?
1-2atm
Why is this pressure used for the Contact process?
favours high pressure but it is not economical so low pressure is used and is still effective
What catalyst is used for the Contact Process?
Vanadium oxide
Stages to make dilute sulphuric acid
sulphur dioxide ➡ sulphur trioxide ➡ oleum ➡ dilute sulphuric acid
What are the problems with the Contact Process?
excess sulphur dioxide can cause pollution so excess oxygen is necessary
Uses of sulphuric acid
- detergents
- fertilisers
- paints
Raw material needed for Electrolysis of Brine
salt solution (sodium chloride in solution)
Where is the salt solution obtained from?
underground salt deposits
What is the anode made from?
titanium
What is the cathode made from?
steel
What is the diaphragm made from?
porous material
What is formed at the anode?
1 chlorine molecule (+2 electrons)
What is formed at the cathode?
1 hydrogen molecule
What are the problems with electrolysis of brine?
- chlorine in contact with NaOH reacts to make bleach
- chlorine reacts violently with hydrogen in exposure to sunlight to form hydrogen chloride
What are the three outputs of electrolysis of brine?
- chlorine
- NaOH
- hydrogen
Uses of chlorine
- bleach
- HCl acid
- sterilising agent
- PVC
Uses of NaOH
- bleach
- paper pulp
- soap
- detergent
