Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Make your likes visible on Facebook?

Connect your Facebook account to Prezi and let your likes appear on your timeline.
You can change this under Settings & Account at any time.

No, thanks

Chemical equlibria and the Haber process

AQA C3 chemistry 2013
by

Paul Scarbrough

on 6 April 2013

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Chemical equlibria and the Haber process

and the Haber Process Chemical Equlibria Chemical Equlibria What is a chemical equlibrium?

Definition...

When a reversible reaction occurs in a closed system, an equlibrium is reached when the reactions occur at exactly the same rate in each direction. Altering Conditions The relative amounts of all the reacting substances at equlibrium depend on the conditions of the reaction.

The reaction conditions you need to know about are:

Temperature
Pressure The Haber Process Economics of the
Haber Process What are the optimum conditions in this industrial process?
Temperature
Pressure

How do they effect
Yield?
Rate? At a dynamic equlibrium reactions are still happening! It just looks like its stopped! Henri Le Chatelier Any change imposed on a system at a dynamic equlibrium will cause it to shift in the direction that opposes the change. What this means is that reactions at equlibrium want to stay there.

So:

if you heat it up, the reaction will increase the direction that will cool down the reaction.
if you lower the pressure the reaction will increase the direction that increases the pressure. If the temperature is raised, the yield from the endothermic direction increases and the yield from the exothermic direction decreases. If the temperature is lowered, the yield from the exothermic direction increases and the yield from the endothermic direction decreases. In gaseous reactions, an increase in pressure will favour the direction that produces the least number of molecules as shown in the balanced equation. 2 Moles 1 Mole Higher
pressure Lower
pressure Making Ammonia Exothermic Endothermic So...
if you raise the temperature you will encourage the endothermic direction (to cool the reaction down).
if you lower the temperature you will encourage the exothermic direction (to warm the reaction up). 4 Moles 2 Moles High
pressure Low
pressure So...
if you raise the pressure you will encourage the low pressure direction (to reduce the pressure).
if you lower the pressure you will encourage the high pressure direction (to increase the pressure). BUT! You must not forget about the effect on the rate of reaction!

low temperature slows down reactions
high temperature speeds up reactions

low pressure slows down reactions
high pressure speeds up reactions Remember...

heating a process is expensive
high pressures are dangerous and expensive to maintain
if the rate of a reaction is very slow it may not produce enough product to make it economic Fritz
Haber Questions?
Full transcript