know that an iron catalyst is used during the haber process explain the choice of temperature and...
TRANSCRIPT
Conditions of the Haber Process..
• Know that an Iron Catalyst is used during the Haber Process
• Explain the choice of temperature and pressure used
• Explain the importance of recycling the Nitrogen and Hydrogen
N2 + H2 NH3
1. Balance the Equation 2. Name the catalyst missing from the
equation3. Explain how the catalyst affects the
reaction
............
A catalyst will lower the activation energy - hence increases the reaction rate, while
remaining chemically unchanged at the end
of the reaction.
Catalyst No Catalyst
Am
ount
Add
ed
Nitrogen + Hydrogen = Ammonia
Activation Energy with a:
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represented on the graph
Conditions used...
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Conditions used...
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Read the instructions in the magnifying glass to see how to use the next slide!
The forward reaction is exothermic so if we carry out the reaction at a lower temperature we will get a higher yield of ammonia.
When the temperature is low the reaction is slow, in industry time is money !
A compromise is made with the temperature. To ensure a reasonable yield is collected at a reasonable rate, a reasonably high temperature is used.
The higher the pressure the higher the yield. However, high pressures are expensive and dangerous.
A compromise is made with the pressure. The company will weigh up the cost of the high pressure with the yield produced. This usually means the pressure is between 200 and 350 atm.
On each pass through the process only about 15% conversion occurs, but any unreacted gases are recycled, so that eventually an overall conversion of 98% can be achieved. This is why recycling the gases is so important.
What temperature gives the highest yield
What pressure gives the highest yield
Why use a catalyst?
What does a low
temperature produce
Explain the reasons for using a reasonably high temperature in industry
Explain the reasons for using a pressure between 200 – 350 atm in industry
Why recycle the Nitrogen and Hydrogen?
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Think – Pair share and peer marking could be
used for pupils to obtain their answer
Design an APP for the new PEAR tablet...
FACTORY FANTASIE’S
Manage your own Haber Processing Factory
Choose your upgrades
Get a Porsche for your Bonus
You set the Temperature, Pressure, Workers Pay!
Aim: You choose!
PEAR Show instructionsHide instructions
Click on the green button at the bottom
of the screen
FACTORY FANTASIE’S
Stage One.....
Choose your site...
FACTORY FANTASIE’S
Stage Two.....
Choose your manager... and set the Pay! (be careful, each
manager has their own advantages and disadvantages).
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Click Activity Suggestion to gain an
insight into the activity
Click on the left green oval
Click on the right green oval
Activity SuggestionActivity Suggestion
Pupils create a game based on running a factory that allows the gamer to control everything i.e. increase pressure to a very high point allowing them to maximise the yield, however this will be very costly. The bosses can have different methods if they use the example to start them off (for example, one boss could be a risk taker, another very focused on cost, another very focused on the yield and not worried about money). It will be up to the teacher to decide the limitations . There are numerous ways to make the activity varied. After this the pupils can switch their game designs with each other. This is just a suggestion, an example to give the pupils an idea
FACTORY FANTASIE’S
Stage Three.....
Set the Temperature...
FACTORY FANTASIE’S
Stage Four.....
Set the Pressure...
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Click lesson idea to gain an insight into the
activity
Click on the left green oval
Click on the right green oval
FACTORY FANTASIE’S
Final Stage...Produce a Report..
How much Ammonia will you make?
How Quickly will you produce the ammonia?
Have you remembered to use a catalyst?
Will your plant be able to run for years to come?
Have you made it too expensive?
What conditions did you choose?
To Summarize
An Iron
catalyst is
used in the
Haber Process
A compromise
is made for the
conditions of
the reaction.
450 and 200 –
350atm.
For an efficient conversion It is very important that the unused Nitrogen
and Hydrogen is recycled back into
the reaction
I can’t wait to get on my Pear Pad when I get home... I will get
the best yield this time?