Le chateliers principle (1 Viewer)

[Will Hunting]

No. It would go to the right. There is less pressure there, which is where it wants to go.

You've increased pressure, so it wants to decrease pressure. It can do this by going forwards because there's only 1 mole on the right compared to 2 on the left.

Oh, and since pressure is proportional to temperature, would increasing the temperature also cause the equilibrium to go to the right, in this case?

Misplaced rhetoric. The reaction is exothermic in the forward direction, therefore equilibrium will shift in the heat-absorbing, or endothermic direction, and H2CO3 will decompose to CO2 (By LCP, eqm shift to left). Pressure, in the sense of the total pressure acting on the system, and not of [CO2] (though temperature changes do alter the solubility of CO2, and, therefore, concentration), is inversely proportional, not directly proportional, to temperature; though, this take is unnecessarily recondite. If you picture an appreciation in temperature as an appreciation in the KE of particles, it makes sense that these particles will, because of their increased mobility, occupy larger volumes. Since an increase in volume = a decrease in pressure, temperature has an inverse relationship to pressure.

 

[Ghost1788]

For all those ppl doing Physics and Chemistry

I dunno how this may help but i associate Le Chatelier's Principle with 1 of Newton's Laws of Motion

Newton said -> for every action there is an equal but opposite reaction

Le Chatelier - > If an equilibrium system is altered in the sense of Concentration, Temperature or Pressure then the system(reaction) will shift as to oppose this change

Hope it helps

 

[Will Hunting]

Sweet stuff, man! I sorta do the same thing, but with Lenz's Law instead!

Physics: An induced EMF will flow so that its associated magnetic field opposes the change in magnetic flux that brought it on

Chemistry: A chemical system will oppose any change to its equilibrium position

Another handy little way

 

[Ghost1788]

thats preety good they are closely related i will follow ur way and then link chatelier to Newton i haw trouble remembering Lenz, thanks bro...

 

[lilkatie]

Hang on i do beleive the syllabus pont says 'identify factors which affect equilibrium'
so we just have to know that temp, conc & pressure affect equilibrium.
I don't think they can ask you to predict which way it will go
they might say 'which way will this eqn go if it;s heated' and you reply 'the other way'

 

[Dreamerish*~]

i've learnt that when pressure is applied, the equilibrium will shift to the side with less moles.

for the equation CO_2(g) + H₂O_(l) --> H₂CO_3(aq)

there are 2 moles on the left side: CO₂ and H₂O
there is 1 mole on the right side: H₂CO₃

therefore when pressure is applied the equilibrium will shift to the right.

 

[funking_you]

Hang on i do beleive the syllabus pont says 'identify factors which affect equilibrium'
so we just have to know that temp, conc & pressure affect equilibrium.
I don't think they can ask you to predict which way it will go
they might say 'which way will this eqn go if it;s heated' and you reply 'the other way'

Students must understand that the syllabus is not written for students, it is written for teachers, it outlines to the teacher what they must teach and outlines the basic concepts that students must learn.
These two points in the syllabus:

• define Le Chatelier’s principle

• identify factors which can affect the equilibrium in a reversible reaction

entail a lot of learning.

I have attached a simplified ChemCoach Worksheet on Equilibrium Systems, which i STRONGLY recommend you download, print and study!.
It covers all that you need to learn, to master these two syllabus point.

Best of luck.
george


GET THE DOCUMENT HERE....

 

[Sirius Black]

i've learnt that when pressure is applied, the equilibrium will shift to the side with less moles.

for the equation CO_2(g) + H₂O_(l) --> H₂CO_3(aq)

there are 2 moles on the left side: CO₂ and H₂O
there is 1 mole on the right side: H₂CO₃

therefore when pressure is applied the equilibrium will shift to the right.

You got the right answer but there is a bit prob in ur explaination[sorrie~~]. In factm the effect of change in presure only applies to gas i.e. liquid or aquous solutrion will not take in account. In this case, there is only 1 mol of gas on LHS and non on RHS thus the equil will shift to the right if the pressure is increased.