P2 - 10.7 The Haber Process Flashcards
Using Resources
What is the haber process
The production of ammonia from nitrogen and hydrogen
What is the haber process
The production of ammonia from nitrogen and hydrogen
What is this process:
N2 + 3H2 <-> 2NH3 (+ heat)
Haber process
What is a reversible reaction
Where reactants can be turned into products and products can be turned back into reactant
Is the haber process a reversible reaction
Yes
What temperature is the haber process done at
450°C
What pressure is the haber process done at
200 atm (atmospheres)
What type of catalyst is used in the haber process
Iron catalyst
True or False: the haber process is one of the most important reactions in the world
True
In the haber process what is the product ammonia used for
To make nitrogen based fertilisers
What do nitrogen based fertilisers do
Helps increase food production
Where do we get nitrogen from for the haber process
The air (makes up 78%)
How much nitrogen is in the air
78%
How do we get hydrogen for the haber process
We have to make it from hydrocarbons like methane
Is the haber process endothermic or exothermic
Exothermic (releases energy to surroundings)
What is the first step in the haber process
Feeding the nitrogen and hydrogen into the top left where they can mix together
What is the first area of the haber process called
Reaction vessel
In the reaction vessel what is the temperature
450°C
In the reaction vessel what is the pressure
200atm (atmospheres)
Where is the iron catalyst in the haber process
Inside the reaction vessel in the middle of the
True or False: gases can freely pass through the iron catalyst in the haber process
True
Whilst inside the reaction vessel what does hydrogen and nitrogen form when reacted together
Ammonia
True or False: in the haber process it is a compound formed in the reaction vessel
False it is a mixture
What elements can you find in the reaction vessel during the haber process
Ammonia
Nitrogen
Hydrogen
Does ammonia have a high or low boiling point
Fairly low
What is the second step of the haber process
Nitrogen and hydrogen mix together to form ammonia
What is the third step of the haber process
Ammonia goes through a pipe into an area called the condensor, which condenses the gas turning into a liquid
Hydrogen and nitrogen don’t condense due to low boiling points and are recycled back around to the reaction vessel
What happens in the condensor
- gaseous ammonia is condensed into liquid ammonia due to low BP
- hydrogen and nitrogen stay in gaseous form and are recycled back into reaction vessel due to low BP
Is the condenser hot or cold
Cold
What is the symbol equation for the haber process
N2 + 3H2 <-> 2NH3 (+ heat)
->
Iron catalyst
450°C
200atm
What 3 things do we need to consider when looking at why the temperature in the haber process is 450°C and the pressure is 200atm
% yield
Rate of reaction
Cost
Why is the temperature in the haber process at 450°C
- because it is exothermic, it needs a low temp to favour forward reaction to achieve higher % yield
- it needs a higher temperature to increase rate of reaction as particles need lots of kinetic energy in order to react
- chosen as a compromise as it produces a lower yield but a higher rate of reaction
- generating heat is expensive so using a high temp is very costly
Why is the pressure in the haber process at 200atm
- to achieve a higher % yield by having a high pressure (means there are fewer molecules of product than there are reactants) - pushes equilibrium to the right
- higher pressure increases rate of reaction, higher pressure means particles collide more frequently
- high pressure is limited by cost and safety as maintaining a high pressure is costly and if it goes wrong it can be very dangerous
What is the word equation for the haber process
Nitrogen + hydrogen <-> ammonia
