Heat of formation doesnt make any sense??

[chaser0]

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Lets say we have compound A and compound B.
A has a heat of formation of -2000
B has a heat of formation of -100
Hence A is considered to release the most energy.

Why?

When you calculate the heat of reaction, you SUBTRACT the reactant heat of formation.

hence A would require +2000 and B would require just +100.

Hence B should release more energy. What am i missing???

 

[rgk27]

I think it should be thought of more as change in Enthalpy with deltaH (exothermic) is reactants going to products + heat. Therefore, a greater exothermic reaction releases more heat, which is in turn more energy since they go hand in hand. If it was endo heat would be on the reactants side and energy would need to be consumed

 

[MedPR]

Lets say we have compound A and compound B.
A has a heat of formation of -2000
B has a heat of formation of -100
Hence A is considered to release the most energy.

Why?

When you calculate the heat of reaction, you SUBTRACT the reactant heat of formation.

hence A would require +2000 and B would require just +100.

Hence B should release more energy. What am i missing???

When bonds form energy is released (is exothermic). -2000 is greater than -100, so A releases more heat (energy).