affect change in pressure has on concentration

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Emily Kennedy 4L
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affect change in pressure has on concentration

Postby Emily Kennedy 4L » Sun Jan 13, 2019 5:47 pm

I don't quite understand why it is a change in concentration instead of a change in pressure.

Jack DeLeon 1B
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Joined: Fri Sep 28, 2018 12:20 am

Re: affect change in pressure has on concentration

Postby Jack DeLeon 1B » Sun Jan 13, 2019 6:49 pm

I am not 100% sure what the question is, but i can clear up Le Chatelier's Principle when it comes to volume and pressure's effects on concentration. A change in pressure will not affect the equilibrium constant of the reaction, but it can change the direction that the reaction shifts. The pressure cannot be changed by adding more of the substances being reacted however. The reaction will only respond to a change in volume (e.g. a move to a smaller container). When the size of the container is changed, the concentrations will change because concentration is moles/Liters, and as long as the number of moles remains constant, the concentration will change as the volume changes. This process is a change in pressure as well because the volume is altered.

Laura Gong 3H
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Re: affect change in pressure has on concentration

Postby Laura Gong 3H » Mon Jan 14, 2019 2:34 pm

Pressure and concentration are related by the ideal gas law: PV=nRT. When you rearrange the equation, P=(n/V)RT where (n/V) is equal to concentration (mol/L).
When you increase pressure by decreasing pressure, the value of V in the denominator decreases, thereby increasing the concentration.


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