Change in Pressure

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Eileen Quach Dis 2A
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Change in Pressure

Postby Eileen Quach Dis 2A » Fri Jan 08, 2021 1:42 pm

During today's lecture, Professor Lavelle said that a change in pressure would cause an increase in concentration. I was wondering why that is?

Ryan_Page_1J
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Re: Change in Pressure

Postby Ryan_Page_1J » Fri Jan 08, 2021 1:46 pm

Picture the equation C=n/v
When you are increasing pressure you are essentially decreasing the volume(picture the piston he used as an example)
So because the denominator (volume) decreases, the concentration(C) will increase.
Keep in mind that this is not the case when adding an inert gas, the way pressure is added is important.

Malakai Espinosa 3E
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Re: Change in Pressure

Postby Malakai Espinosa 3E » Fri Jan 08, 2021 1:48 pm

The change in pressure only increases the concentration if the change is a result in a decrease of volume. concentration=moles/volume. The moles stays constant but the volume decreases, so the concentration increases.

lwon Dis2I
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Re: Change in Pressure

Postby lwon Dis2I » Fri Jan 08, 2021 8:32 pm

Why does inert gas not apply to the same rule of the effect of changing the pressure on the concentration?

Joey_Okumura_1E
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Re: Change in Pressure

Postby Joey_Okumura_1E » Fri Jan 08, 2021 8:41 pm

Changing the pressure will only change the concentration if it also changes the volume since C=n/V.
If the container is compressed, the volume will decrease and therefore concentration will increase.
Adding an inert gas increases pressure because the added gas will cause more force will be exerted on the container. However, the volume of the container does not change. Therefore, the concentration also remains the same.

Amanda Chang 2B
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Re: Change in Pressure

Postby Amanda Chang 2B » Sat Jan 09, 2021 5:46 pm

Increasing pressure by adding an inert gas when volume is constant does not apply to the same rule. This has to do with inert gases being non-reactive. Since these gases are non-reactive, the partial pressures of the reactants and products are unaffected. Thus, equilibrium is unaffected. The total pressure of the system has increased but the partial pressures of the reactants and products have not.

keely_bales_1f
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Re: Change in Pressure

Postby keely_bales_1f » Sat Jan 09, 2021 5:49 pm

By increasing the pressure (only applies to gases), you would be decreasing the overall volume. This would result in an increase of concentration.

rhettfarmer-3H
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Re: Change in Pressure

Postby rhettfarmer-3H » Sun Jan 10, 2021 7:10 pm

Not every time does a change in pressure mean a change in concentration, only when compressed or expanded. We Can agree that concentration is made by n/V which means it is dependent on moles and volume. If we compress the system we are changing the pressure but we are also changing the volume. This is what he meant when it changes concentration as seen as volume changes so does the Concentration because it is dependent on volume.

Danielle DIS2L
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Re: Change in Pressure

Postby Danielle DIS2L » Sun Jan 10, 2021 9:06 pm

By increasing the pressure, there would be a decrease in volume because they have an inverse relationship which would result in an increase of concentration

Ethan Laureano 3H
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Re: Change in Pressure

Postby Ethan Laureano 3H » Sun Jan 10, 2021 9:33 pm

Like many have stated, changing pressure changes concentration because of the change in volume associated. However, not all changes to pressure result or is the result of a change in volume (i.e. adding an inert gas).


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