[justkeepmoving]

I appreciate any insight into this problem. From what I understand about Kinetics so far is that 1. We look at the Average Kinetic energy of a substance because there is a range of Kinetic Energies in substances. 2. Some factors that affect kinetic energy are temperature, concentration, surface area of reactants & enzymes (catalysts) .
So when I look at this problem from Wiley (http://www.wiley.com/college/boyer/0470003790/reviews/kinetics/Q_effectors.htm) my first instinct is to say that the whole curve would shift to the right (answer choice 'A') when the temperature of the vessel is raised to 50 degrees C. My explanation (or defense) for this choice is that, the average KE should increase and this should be expressed by a curve shift along the X-axis to the right. However, according to Wiley this is incorrect and for the life of me I do not understand why they are saying this curve would shift left (answer choice B).
I tried thinking outside the box (at the risk of 'overthinking' the problem) and came up with, the idea that Wiley is wanting me to recognize that as the Temperature changes, some of the C02 particles will reach the activation energy and 'leave' the system in another phase. However, this is a gas (starts as a gas at 25 degrees and remains a gas at 50 degrees). And the only way 50 Degrees of CO2 is in a state other than Gas is if the pressure is WAY high and even then I think this would probably designate a supercritical fluid. Plus, the shape of the curve would change if indeed any particles do leave the system and would still shift right!
Now I may be venturing outside the scope of what I think this question is testing. So I am thinking this is an error on Wiley's part?

[AdiDex]

As far as I know Average kinetic energy per mole(or per molecule) only depends upon Temperature (Neither on Concentration nor on catalyst   nor on surface area ) .

Answer must be A . (Answer given by willey is wrong , but their explanation is correct but they mentioned something wrong. The wrong thing is that they mentioned "shape of the curve will remain the same" , which is wrong the curve will become little bit flatter , in order to keep the area below the curve constant )

as the Temperature changes, some of the C02 particles will reach the activation energy and 'leave' the system in another phase. However, this is a gas (starts as a gas at 25 degrees and remains a gas at 50 degrees). And the only way 50 Degrees of CO2 is in a state other than Gas is if the pressure is WAY high and even then I think this would probably designate a supercritical fluid. Plus, the shape of the curve would change if indeed any particles do leave the system and would still shift right!

We took Fraction of molecules on y axis , there will be no difference if you take 2 mol particles or 1 mol particles .

But there is problem if you are taking a open container , there will be some complication . let me think about it i will reply  later .

[justkeepmoving]

Yes you are correct it is just Temperature. Sorry! For some reason i was thinking about the rate of a reaction with regards to surface area, concentration etc.

Thank you for your response! So why would there be a need to flatten out the curve a bit if you increase the temperature? Doesn't shifting the average KE curve to the right keep the area below the curve consistent?

[AdiDex]

Sorry this is not a perfect sketch (I am not a good artist  )

What I have drawn , f(x)' is just a extended version of f(x) , in which 1' point  corresponds to 1 point , 2' point corresponds to point 2 , point 3' corresponds to point 3 .
Area from 1 to infinity (under f(x)  curve) will be equal to area from 1' to infinity (under the f(x)' curve) . Do you agree ??

If this is so then there will be an extra area under the f'(x) before the point 1' .

Area must be remain constant to keep the no. of molecule constant . Due to this reason f'(x) must be flatter .

[justkeepmoving]

Ahhh yes, thank you for sketching those! It helped me understand this better. I really appreciate your *delete me*

[mjc123]

Strictly speaking the curve is not shifted to the right, but stretched along the x axis; the distribution is broader at higher temp, with a higher average, so it is flattened to keep the total area constant, like this: