How would you draw and label energy diagrams that depict the following reactions, and determine all remaining values? Place the reactants at energy level zero

enter image source here

1 Answer
May 18, 2017

We would split up the given values in terms of thermodynamics and kinetics for the reactions.

Thermodynamics

DeltaE'_(fwd) = -"10 kJ/mol"
DeltaE'_(rev) = -"40 kJ/mol"

DeltaE_(fwd) = -"95 kJ/mol"

Kinetics

E_a' (fwd) = "40 kJ/mol"
E_a' (rev) = "30 kJ/mol"

E_a (fwd) = "20 kJ/mol"

The thermodynamic values correspond to the reactants vs. products. The kinetic values correspond to the reactants vs. transition state.

As they are, the values don't seem to make sense... there is an E_a' (fwd) and an E_a' (rev), which seem to indicate the same reaction.

Yet, if we have two reactions with activation energies E_a and E_a' and reaction energies DeltaE and DeltaE', then we should have |DeltaE_(fwd)| = |DeltaE_(rev)|, but |-"10 kJ/mol"| ne |-"40 kJ/mol"|.

I'll let you work from the qualitative picture up above...