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Activation Energy and Energy released/absorbed

Posted: Sat Mar 14, 2020 12:01 pm
by Siddiq 1E
I was looking at the graphs for endothermic and exothermic reactions and I wanted clarification about whether in an endothermic reaction, the amount of activation energy includes the amount of energy that is absorbed in the reaction?

Re: Activation Energy and Energy released/absorbed

Posted: Sat Mar 14, 2020 1:39 pm
by Ipsita Srinivas 1K
The energy absorbed includes the activation energy needed for the reaction to take place for both endothermic and exothermic reactions. In the case of exothermic reactions, energy related on product formation is more than energy absorbed for overcoming energy barrier, and hence there is a net loss of energy.

Re: Activation Energy and Energy released/absorbed

Posted: Sat Mar 14, 2020 2:07 pm
by Jared_Yuge
activation energy is always accounted for in both endo and exothermic reactions, but that doesn't determine net loss/gain of energy

Re: Activation Energy and Energy released/absorbed

Posted: Sat Mar 14, 2020 2:36 pm
by Frank He 4G
The net energy change of a reaction includes the activation energy, not the other way around, for both endothermic and exothermic reactions. In general, if you are trying to determine the net energy change from a reaction profile, all you need to look at is the initial and final energies. Remember that reaction profiles represent the energy as the reaction proceeds, so if the curve goes higher, energy is being put in, and if the curve slopes downwards, energy is being released. Thus, a curve that goes up and then goes down the same amount means that the reaction absorbs energy and then releases the same amount of energy.