Chemical Kinetics

[deleted801953]

---

Members do not see this ad.

when talking about reaction diagram for formation of a compound, a note on the side says-
"Note that the free energy of the products can be raised or lowered, thereby changing the vaue of Delta G without affecting value of Ea"
Can someone explain how this is possible/ link a video that explains it?
Thanks

 

[663697]

Notice that the product's free energy is not dependent on the maximum on the graph (which is the activation energy)? Imagine shifting "C+D" up or down, which changes the free energy. The activation energy still remains the same.

 

[deleted801953]

Thanks Cuttlefish, my question though is how is it possible to shift the energy of C+D (ie up and down)? I thought products would usually have a constant energy value?

Everything else makes sense

 

[Doogie.Howser]

You can change deltaG by changing temperature. Recall deltaG = deltaH - TdeltaS. There is a constant value of H and S for a reaction, but temperature changes the deltaG value.

I believe that the side note is trying to tell you that activation energy and deltaG are independent of each other. You can change deltaG without changing the activation energy.

 

[deleted801953]

Awesome, yeah that makes sense! Thanks a lot everyone