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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: orchid on June 12, 2006, 10:50:55 PM

Title: Claus Process & Le Chatelier's Principle
Post by: orchid on June 12, 2006, 10:50:55 PM
Hello everyone! I need help on a question regarding Le Chatelier's Principle.

The Claus Process is an industrial process used to remove toxic hydrogen sulfide gas during the processing of crude oil. The chemical equation for this process is: 2H2S(g) + SO2(g) <-> 3S(s) + 2H20(g) + heat. Use Le Chatelier's Principle to describe why the following changes favour the removal of H2S.

a) Removing sulfur as soon as it forms.
b) Cooling the reaction chamber.


Okay, his principle states that when a stress is applied to a system at equilibrium, the system readjusts so it can relieve or offset the stress. So would it be because that since it is removing H2S, the formula is relieved? Thanks in advance!!!  :)
Title: Re: Le Chatelier's Principle
Post by: Yggdrasil on June 13, 2006, 12:15:11 AM
Basically, the basis of Le Chatalier's principle is that if you add a reactant or product, the reaction will shift to favor the removal of that reactant or product.  If you remove a reactant or product, the reaction will shift to form that reactant or product.

So, in case (a), you are removing S(s).  Since this is a product, the equilibrium will shift to form more S.  This will consequently promote the removal of H2S because H2S is used up in the production of sulfur.

For (b), you can think of cooling the reaction as removing heat.  Since heat is a product of the reaction, its removal will cause the reaction to favor the production of more heat.
Title: Re: Le Chatelier's Principle
Post by: orchid on June 13, 2006, 12:26:27 AM
Thank you very much!
Title: Re: Claus Process & Le Chatelier's Principle
Post by: jennielynn_1980 on September 28, 2006, 03:03:51 PM
I have a question in regards to part b).  I see how cooling the chamber will favour the production of more heat.  So how does this favour the removal of H2S?  Is it because the equilibrium will shift right to replace the lost heat and in doing so also produce more S(s) which will in turn promote the removal of H2S because H2S is used in the production of sulphur solid?

Thanks:)
Title: Re: Claus Process & Le Chatelier's Principle
Post by: Donaldson Tan on September 28, 2006, 03:24:24 PM
jennielyn_1980: yes