Inert Gases
Moderators: Chem_Mod, Chem_Admin
-
- Posts: 144
- Joined: Thu Feb 27, 2020 12:16 am
Inert Gases
Why changing the pressure of a reaction with an inert gas not affect reactant and product concentration? Why does it have no effect on reaction? Does it just change the pressure and nothing else?
-
- Posts: 95
- Joined: Wed Sep 30, 2020 9:49 pm
Re: Inert Gases
I think it's because 1. the inert gas is not participating in the reaction and therefore does not effect the K value itself and 2. When you add the gas it will effect the partial pressures of both the products and reactants meaning while each individual value changes, they remain proportional which would keep K the same because it is just a ratio of products to reactants.
-
- Posts: 100
- Joined: Wed Sep 30, 2020 9:48 pm
Re: Inert Gases
Hi! I believe that adding an inert gas does not change the concentrations of the reactant or product because it doesn't react with any part of the equilibrium reaction, which is just a property of inert gases. I believe the reason Lavelle brought this up in lecture was to highlight that you can't always say that changing pressure will affect the reaction, it's more about HOW the pressure is being changed. Hope this helps!
-
- Posts: 101
- Joined: Wed Sep 30, 2020 9:52 pm
Re: Inert Gases
An inert gas does not change the volume. K is always calculated in terms of quanitity per volume, hence increasing pressure with an inert gas does nothing to change it.
-
- Posts: 104
- Joined: Wed Sep 30, 2020 9:37 pm
Re: Inert Gases
This is because an inert gas does not contribute to the volume. Because K is calculated in terms of concentration, the inert gas would not contribute to this in the equation.
-
- Posts: 108
- Joined: Wed Sep 30, 2020 10:00 pm
Re: Inert Gases
I’m confused on how this situation presented in 5J of the book can be true if adding gases doesn’t change pressure which then doesn’t effect concentration: “Suppose that the ammonia synthesis reaction, reaction A, has reached equilibrium. Now suppose that more hydrogen gas is pumped in. According to Le Chatelier’s principle, the increase in the concentration of hydrogen molecules will tend to be minimized by the reaction hydrogen with nitrogen. As a result, additional ammonia will be formed.”
-
- Posts: 51
- Joined: Mon Jan 04, 2021 12:09 pm
Re: Inert Gases
Ellison Gonzales 1H wrote:I’m confused on how this situation presented in 5J of the book can be true if adding gases doesn’t change pressure which then doesn’t effect concentration: “Suppose that the ammonia synthesis reaction, reaction A, has reached equilibrium. Now suppose that more hydrogen gas is pumped in. According to Le Chatelier’s principle, the increase in the concentration of hydrogen molecules will tend to be minimized by the reaction hydrogen with nitrogen. As a result, additional ammonia will be formed.”
I believe that it was specifically adding inert/noble gases doesn't affect concentration, and hydrogen gas isn't inert.
-
- Posts: 101
- Joined: Wed Sep 30, 2020 9:42 pm
Re: Inert Gases
Changing the pressure will not change the concentrations because we calculate K through quantity per volume, and an inert gas does not affect the equilibrium reaction.
-
- Posts: 81
- Joined: Fri Aug 30, 2019 12:17 am
Re: Inert Gases
When you add an inert gas to a closed system, you aren't decreasing the concentrations of the gasses already in the system, you are just adding that inert gas in as well. Because of this, K is not affected and therefore equilibrium remains unchanged.
-
- Posts: 109
- Joined: Wed Sep 30, 2020 9:59 pm
Re: Inert Gases
Hi. Dr. Lavelle brought this up to demonstrate that the change caused by adding/deducting pressure isn't strictly associated by moles of gases. It's associated with concentration of gases. Adding an inert gas to a container with fixed volume only changes pressure. It does not participate in the reaction therefore the concentrations of the reactants and products are the same as before.
-
- Posts: 106
- Joined: Wed Sep 30, 2020 10:02 pm
Re: Inert Gases
The inert gas does not react in the reaction because it doesnt affect any of the products or reactants. therefore it K is unchanged.
-
- Posts: 179
- Joined: Thu Dec 17, 2020 12:19 am
Re: Inert Gases
Changing the pressure doesn't necessarily affect the position of equilibrium. Only changes in concentration affect the position of equilibrium. If we increase the pressure and the volume of the system decreases, the concentrations change (remember, they're expressed as mol/volume, so if volume changes, concentration changes). Adding an inert gas does not affect the partial pressures of the gases in the system, thus not shifting the position of equilibrium.
Who is online
Users browsing this forum: No registered users and 7 guests