Reverse Reation

[nina_rox]

I'm having trouble drawing and finding the activation energy for the reverse reaction. For example if I was given an reaction and I wanted to draw the reverse reaction what of the of the original reaction corresponds to this activation energy of the reverse reaction?

Also another side question: On the graphs is there two sections called the activation energy? (from reactant to top of peak and top of peak to products? I'm so confusedd..

Any help would be really appreciated!! Thank you.

[ligands]

On the graph, the reactants to the top of the peak is the activation energy and the products to the peak is the energy gained from the reaction

[DisaFear]

Source

The forward is exothermic, the backward is endothermic

[nacho]

this thread title

[nina_rox]

Thank you very much! That was very helpful!

So if I had say the delta H of an reaction and its value of activation energy what would the activation energy of the reverse reaction? I know the delta H's sign changes in its reverse reaction but not sure what happens with its activation energy because it certainly isn't the same...

[DisaFear]

Thank you very much! That was very helpful!

So if I had say the delta H of an reaction and its value of activation energy what would the activation energy of the reverse reaction? I know the delta H's sign changes in its reverse reaction but not sure what happens with its activation energy because it certainly isn't the same...

I don't trust myself enough to answer this correctly. But if you look at the graph, and read the info, it says that the activation energy is always positive.
226kJ + 134kJ = 360kJ
360kJ - 226kJ = 134kJ

Maybe someone more knowledgeable can help you here, but that's the only patterns I can see

[nina_rox]

Thank you very much!

[MagicGecko]

yeah DisaFear is right, the activation energy of any reaction is ALWAYS positive. this makes it easy in multiple choice question where you can just eliminate the negative ones

[SenriAkane]

Drawing the backward reaction is really drawing the forward reaction reflected in the y-axis ( remember to change the location of zero enthalpy)

[WhoTookMyUsername]

will the forward and reverse reaction ALWAYS occur to some extent? (for any reaction in any conditions except absolute zero?)

[Jenny_2108]

Iam not sure but I think only some reaction can be reversed if they are incomplete

[charmanderp]

will the forward and reverse reaction ALWAYS occur to some extent? (for any reaction in any conditions except absolute zero?)

Yes, so long as each species is always present in the reaction mixture. I guess if you had a volatile species then the reverse reaction would cease at some point of that evaporated, etc.