Question about activation energy and reaction rates.

AI Thread Summary
Temperature increases kinetic energy, leading to more collisions and generally higher reaction rates. However, in nucleophilic reactions, stronger solvation of the nucleophile raises the energy needed to remove it from its solvation shell, which can lower the reaction rate. This creates a seeming contradiction between the effects of temperature on reaction rates and the impact of solvation energy. The discussion emphasizes that these concepts involve different types of energy, making direct comparisons misleading. Understanding the distinction between internal energy and activation energy is crucial for resolving these contradictions.
yungwun22
Messages
19
Reaction score
0

Homework Statement


I know that temperature and kinetic energy are related, so as temperature increases the energy of the reactants as well as the amount of collisions and bonds formed, increases. I take this as meaning that the rate increases. But I also read in my organic book that in nucleophilic reactions, the stronger the solvation of the nucleophile, the greater the energy required to remove the nucleophile from it's solvation shell to reach the solvation state will be, lowering the rate of reaction. These ideas seem contradictory.



Homework Equations





The Attempt at a Solution


I think the first idea has to do more with internal energy of the system and the second with activation energy in terms of maybe Gibbs free energy or enthalpy, but I'm not too sure.
 
Physics news on Phys.org
You are comparing apples and oranges. Try to elaborate on why do you think these ideas are contradictory.
 
Borek said:
Try to elaborate on why do you think these ideas are contradictory.

Because the rate increases in the first and decreases in the second, but that there is an increase of energy in both scenarios. I felt that there should be a high reaction rate in the second scenario as well.
 
These are completely different energies, so you can't compare them.
 
Thread 'Confusion regarding a chemical kinetics problem'
TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
Back
Top