Heat of Hydrogenation and Stability question?

[GomerPyle]

Time to bug you guys again with questions! Hey...it is good practice for ya'll!

Apparently, the more stable an alkene, the less the heat of hydrogenation.

To me, it is more intuitive that the less stable an alkene is, the more it wants to be hydrogenated so it can become more stable; therefore, because it wants to be hydrogenated to get out of its unstable state, it would mean a lower heat of hydrogenation. My intuition is wrong, but why??

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[loltopsy]

Bonds are unstable because they have too much energy. Heat of Hydrogenation is a measure of the energy of the bonds in question.

For example, when an electron absorbs energy and moves up from its ground state, it is now in a less stable position. It wants badly to get rid of that energy, and it does, releasing a lot of energy. A different electron dropping to its ground state but at a lower excited state would release less energy. Same concept but with bonds.

 

[Jesus1]

Bonds are unstable because they have too much energy. Heat of Hydrogenation is a measure of the energy of the bonds in question.

For example, when an electron absorbs energy and moves up from its ground state, it is now in a less stable position. It wants badly to get rid of that energy, and it does, releasing a lot of energy. A different electron dropping to its ground state but at a lower excited state would release less energy. Same concept but with bonds.

Easy way to think about it.
Alkanes are typically more stable than alkenes.Therefore,the product of hydrogenation is typically a more stable product than the starting material.
To form a more stable product,you have to lose energy (think of a child that is highly unstable when he has eaten tons of food but becomes more stable and less mobile as hunger sets in).
If you were more stable to start with and you're trying to get to the same base level as another compound,you'll need to lose less energy to achieve the goal you want.
If hunger is the state everyone is trying to achieve (more stability),being a little hungry in the first place means you'll have very little to do before you become really hungry unlike a person that has just eaten a delicacy.
Hope this makes sense.

 

[mehc012]

Easy way to think about it.
Alkanes are typically more stable than alkenes.Therefore,the product of hydrogenation is typically a more stable product than the starting material.
To form a more stable product,you have to lose energy (think of a child that is highly unstable when he has eaten tons of food but becomes more stable and less mobile as hunger sets in).
If you were more stable to start with and you're trying to get to the same base level as another compound,you'll need to lose less energy to achieve the goal you want.
If hunger is the state everyone is trying to achieve (more stability),being a little hungry in the first place means you'll have very little to do before you become really hungry unlike a person that has just eaten a delicacy.
Hope this makes sense.

I want to live where you live, cuz around here hungry people (especially kids) are CRANKY!!