Excess Reactant in Le Chatelier's Principle

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Kevin Xu 4F
Posts: 40
Joined: Fri Aug 09, 2019 12:16 am

Excess Reactant in Le Chatelier's Principle

Postby Kevin Xu 4F » Mon Jan 13, 2020 1:24 am

Let's suppose we have a reaction N2 + 3H2 --> 2NH3. If we add more N2, the reaction by le chatelier's principle shifts to the right. But do we always assume that we have excess reactants? Because what if H2 is the limiting reactant, adding more N2 would not shift the reaction to the right because there is nothing for it to react to in order to form ammonia right?

Amy Pham 1D
Posts: 93
Joined: Fri Aug 09, 2019 12:15 am

Re: Excess Reactant in Le Chatelier's Principle

Postby Amy Pham 1D » Mon Jan 13, 2020 10:17 am

I believe that examining reactions by way of Le Chatelier's Principle functions under the assumption that reactants are in excess. It is a merely conceptual way of understanding how manipulating amounts of products/reactants affects reaction rates, without the added parameter of limiting reactants.

Sam McNeill 1E
Posts: 100
Joined: Sat Aug 24, 2019 12:17 am

Re: Excess Reactant in Le Chatelier's Principle

Postby Sam McNeill 1E » Mon Jan 13, 2020 10:29 am

I think we need to think about it in terms of reactants as a whole and products as a whole and not each individual reactant and product in the reaction, if that clarifies things.

McKenna_4A
Posts: 101
Joined: Sat Aug 24, 2019 12:18 am

Re: Excess Reactant in Le Chatelier's Principle

Postby McKenna_4A » Mon Jan 13, 2020 4:11 pm

This is a good point, but when dealing with equilibrium concentrations, assume the other reactants/products are in excess

Subashni Rajiv 1K
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Joined: Wed Sep 18, 2019 12:16 am

Re: Excess Reactant in Le Chatelier's Principle

Postby Subashni Rajiv 1K » Mon Jan 13, 2020 4:25 pm

When given problems regarding Le Chatelier's Principle, we are to assume that the products and reactants are in excess.

Altamash Mahsud 1I
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Joined: Fri Aug 09, 2019 12:16 am

Re: Excess Reactant in Le Chatelier's Principle

Postby Altamash Mahsud 1I » Mon Jan 13, 2020 6:46 pm

Hey Kevin, when given these types of questions and trying to understand a concept, in this case Le Chatlier's principle, then if the amount of a reactant is not stated in the problem you can assume that it is in excess. Have a good day :)

Abigail_Hagen2G
Posts: 90
Joined: Fri Aug 09, 2019 12:17 am

Re: Excess Reactant in Le Chatelier's Principle

Postby Abigail_Hagen2G » Tue Jan 14, 2020 2:15 pm

The reactants have to be in excess, because Le Chatlier's Principle is based on a reaction in equilibrium, and so it's still going on.


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