Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: lexi105 on November 20, 2006, 02:01:29 AM
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Hello.
I am having a lot of trouble trying to find information on the internet that fully explains the process.
The question is to "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
So here is what I have:
“The Claus Process” is used to remove toxic hydrogen sulfide gas during the processing of crude oil. The following changes of 1) removing sulfur as soon as it forms and 2) cooling the reaction chamber favour the removal of H2S and can be explained using Le Chatelier’s Principle. The reaction in of the process can be shown through 2H2S + SO2 <=> 3S + 2H2O + heat. Sulfur is removed as soon as it forms in order to make pure sulfur. If sulfur is removed additional sulfur from the left side of the equation will have to favour the right side of the equation in order to reach equilibrium.
I am not too sure about the cooling part. Any help would be appreciated. Thanks!
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You can think of cooling as removing heat. What would removing heat do to the reaction?
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Removing heat would affect the equilibrium constant which will decrease the rate of the forward and reverse reactions. Will the rates become equal as the concentrations establish themselves at a new level?
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Try thinking of heat as a product of the reaction.
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So heat is formed on the right side of the equation as a product of the reaction. In order to reach equilibrium the solution is "cooled" in the reaction chamber, which will then favour the left side of the equation.
Was my guess on removing sulfur as soon as it forms right?
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Both explanations are now correct. Removing the sulfur will cause the reaction to favor the production of more sulfur, resulting in the forward reaction being favored and using up H2S. Similarly, removing heat will favor the production of more heat, causing the forward reaction to occur.